Overview

Routing and Remote Access Service for Windows NT Server version 4.0 is an open, extensible platform for routing and internetworking. It enables routing over IP and IPX networks by connecting local area networks (LANs) or by connecting wide area networks (WANs) without requiring the use of a dedicated hardware router.

Routing and Remote Access Service provides a graphical user interface that is easy to use, flexible, and extensible. Routing and Remote Access Service also provides a command-line tool for using batch files.

Routing and Remote Access Service combines routing and remote access technologies. Administrators can use the Routing and RAS Admin tool to view and manage both routers and RAS servers in their network.

Routing and Remote Access Service is designed for use with Windows NT Server version 4.0. The routing currently included with Windows NT Server version 4.0-MultiProtocol Routing (MPR) version 1-is suitable for smaller organizations and branch offices that require limited routing protocol support over LANs. Routing and Remote Access Service extends the internetworking and routing capabilities available in MPR version 1 and enables routing over WANs and demand-dial networks.

 Related Topics


Adding a Routing Protocol

1	In Routing and RAS Admin under IP Routing, right-click Summary, and click Add routing protocol.

2	In the Select Routing Protocol dialog box, click one of the following protocols: DHCP Relay Agent, Open Shortest Path First (OSPF) by Bay Networks, or RIP Version 2 for Internet Protocol.

3	Complete any configuration dialog boxes for the protocol.

 Related Topics


Deleting a Routing Protocol

You must use the command line interface to delete a routing protocol. If the interface is specified, then the routing protocol is removed from only that interface. If the interface is not specified, the protocol is deleted globally as well as from every interface on which it is enabled.

At a command prompt window, type the following syntax:

routemon [\\ComputerName] ip delete protocol
[proto= ] {bootp | rip | ospf}
[ [name= ] InterfaceName]

\\ComputerName

The computer running the router service. The default is the local computer.

[proto= ] {bootp | rip | ospf}

The routing protocol to be deleted, bootp, rip, or ospf. Note: bootp is the DHCP Relay Agent.

[name= ] InterfaceName

The interface from which the protocol is to be deleted.

 Related Topics


Adding a LAN Interface

1	Under IP Routing, right-click a protocol, and click Add interface.

2	Select the interface you want to add and click OK.

3	Configure any parameters for the interface.

Note:	All available IPX routing protocols are added automatically during Routing and Remote Access Setup. To add an interface to IPX, right-click Summary under IPX Routing, and then click Add interface. The interface is added to all IPX protocols.


Adding a Demand-Dial Interface

A demand-dial connection initiates a link to a remote site when data or routing information must be sent to that site, and closes the connection when a specified amount of time has passed without data being sent over the link.

To connect to a demand-dial router, you must first add a demand-dial interface for that router. For example, if you want to configure a dial-up connection from your Seattle office router to the New York branch office router, you must add an interface for New York on the Seattle router.

After adding a demand-dial interface, you must:

Set credentials on the interface to be used for authentication on the remote router.

Add a user account on the remote router that gives you permission to dial into the remote router.

Note:	When you configure a demand-dial interface, you must enable the port usage on the interface for routing. Use Network in Control Panel to configure the Routing and Remote Access Service, select the port, and then click Configure in the Routing and Remote Access Setup dialog box.

Routing and RAS Admin also includes a Demand-Dial Wizard to help you set up demand-dial interfaces. For more information on how to complete this connection, see Making a Demand-Dial Connection.


Making a Demand-Dial Connection

To configure a demand-dial connection between two locations, for example, between New York and Seattle, you must complete a series of procedures.

To make a one-way demand-dial connection from Seattle to New York:

Add an interface on RouterS with the name of "New York."

Add an interface on RouterNY with the name of "Seattle."

On RouterS, set the credentials used when dialing into RouterNY.

On RouterNY, create a user with the user name "Seattle" and password as used in the Credentials dialog box on RouterS.

If you want to make a connection back to Seattle from New York, you must complete a few extra steps. This is essentially the opposite of the configuration you have just completed:

On RouterNY, set credentials on the "Seattle" interface to be used when dialing into RouterS

On RouterS, create a new user with the user name "New York" and password as used in the Credentials dialog box on RouterNY.

The following figure shows an example demand-dial connection from Seattle to New York.

See the following topics for examples of how to complete these steps:

Adding an Interface on the Seattle Router

Adding an Interface on the New York Router

Setting Credentials on the Seattle Router

Creating a User on the New York Router

Setting Credentials on the New York Router

Creating a User on the Seattle Router


Adding an Interface on the Seattle Router

When you dial from Seattle to New York, each router must have an interface that represents the opposite router. The local router uses that interface to identify the remote router dialing in. When a call comes in, the user name of the remote router is matched to an interface on the local router.

The following figure shows an example of the interface "New York" on the Seattle router.

To add an interface on RouterS with the name of "New York"

1	On RouterS, right-click LAN and Demand Dial Interfaces and click to clear Use demand-dial wizard.

2	Right-click LAN and Demand Dial Interfaces again and then click Add interface.

3	On the Basic page, in the Entry name box, type New York.

See the following topic to complete these steps:

Adding an Interface on the New York Router


Adding an Interface on the New York Router

On RouterNY, add an interface. In this case, name the interface "Seattle."

The following figure shows an example of the interface "Seattle" on the New York router

To add an interface on RouterNY with the name of "Seattle"

1	On RouterNY, right-click LAN and Demand Dial Interfaces and click to clear Use demand-dial wizard.

2	Right-click LAN and Demand Dial Interfaces again, and then click Add interface.

3	On the Basic page, in the Entry name box, type Seattle.

See the following topic to complete these steps:

Setting Credentials on the Seattle Router


Setting Credentials on the Seattle Router

Next, you need to set the credentials on the Seattle router to use for dialing into the New York router.

The following figure shows an example of the credentials set on the Seattle router for dialing into the New York router.

To set the credentials on RouterS to use when dialing into RouterNY

1	On RouterS, right-click the New York interface, and click Set Credentials.

2	In the Interface Credentials dialog box, in the Username box, type Seattle.

3	In the Password box, type RouterS' password.

See the following topic to complete these steps:

Creating a User on the New York Router


Creating a User on the New York Router

On RouterNY, you now create a user with the user name "Seattle" and a password, as used in the Credentials dialog box on RouterS.

The following figure shows an example of the user "Seattle" on the New York router

To create a user with the user name "Seattle" on RouterNY

1	On RouterNY, open User Manager for Domains.

2	On the User menu, click New User.

3	In the New User dialog box, in the Username box, type Seattle.

4	In the Password box, type RouterS' password.

You have now completed a demand-dial connection from Seattle to New York. To make a connection back to Seattle from New York see the following procedure.

See the following topic to complete these steps:

Setting Credentials on the New York Router


Setting Credentials on the New York Router

Set the credentials on the New York router to use for dialing into the Seattle router.

The following figure shows an example of the credentials set on the New York router for dialing the Seattle router.

To set the credentials on RouterNY to use when dialing into RouterS

1	On RouterNY, right-click the Seattle interface, and click Set Credentials.

2	In the Interface Credentials dialog box, in the User name box, type New York.

3	In the Password box, type RouterNY's password.

See the following topic to complete these steps:

Creating a User on the Seattle Router


Creating a User on the Seattle Router

Finally, on RouterS, you now create a user with the user name "New York" and a password, as used in the Credentials dialog box on RouterNY.

The following figure shows an example of the user "New York" on the Seattle router.

To create a user with the user name "New York" on RouterS

1	On RouterS, open User Manager for Domains.

2	On the User menu, click New User.

3	In the New User dialog box, in the Username box, type New York.

4	In the Password box, type RouterNY's password.

Note:	After you understand the demand-dial process, you may want to use the same interface name on both sides of the demand-dial connection to simplify the process. For instance, you could use the name Seattle-NewYork on the interface you create on RouterS and as the name of the interface you create on RouterNY. This way, the user names you then create on both routers will also be Seattle-NewYork.

If the routers are in the same domain, you must make sure that every interface name is unique on the local router.


Deleting Interfaces

You can delete an interface from the router, which removes the interface from all routing protocols, or you can delete an interface from a specific protocol.

To delete an interface from the router

1	Under IP Routing or IPX Routing, click Summary.

2	Right-click an interface, and then click Remove interface.

To delete an interface from a routing protocol

1	Under IP Routing, click a protocol.

2	Right-click an interface, and then click Remove interface.

Note:	You cannot delete an interface from a specific IPX protocol.


Adding Static Routes

To add a static route

Under IP or IPX Routing, right-click Static Routes, and then click Add Static Route.

 Related Topics


Deleting Static Routes

To edit or delete a static route

Under IP or IPX Routing, select Static Routes, right-click the route, and click Edit or Remove.

 Related Topics


Administering a Remote Router

You can remotely administer a Windows NT router from Routing and RAS Admin.

In Routing and RAS Admin, in the Server menu, click Connect to Router and type the name or address of the remote router you want to administer.

You can also remotely administer a Windows NT router from a non-Windows NT router (must be a computer running Windows NT version 4.0) by using the copyadmn.cmd batch file. This file is part of the Routing and Remote Access Service files that are copied to your computer when you install Routing and Remote Access Service.

Note:	After copying these files to a Windows NT version 4.0 computer, you cannot use the Windows NT 4.0 RAS client on the computer. This is because some of the .dll files that are copied over are incompatible with .dll files that are part of Windows NT version 4.0. To use a RAS client on the computer, you must upgrade to Routing and Remote Access Service.

To administer a remote Windows NT router from a non-Windows NT router

1	On the Windows NT router, open a Command Prompt window.

2	Run copyadmn.cmd and type the source and destination directories.

For example, type:

copyadmn c:\winnt\system32\ \\admin\dept1\remote

3	On the remote computer (\\admin\dept1 in this example) make a network connection to the Windows NT router.

For example, at the command prompt type:

net use \\router1\ipc$ /u:domain\user

4	On the remote computer, at the command prompt, type mpradmin.

5	In Routing and RAS Admin, in the Server menu, click Connect to Router.

6	In the Server Name box, type the name of the Windows NT router, such as \\router1, and click OK.


Viewing Routing Tables

You can use Routing and RAS Admin to view routing and protocol information when you troubleshoot or administer your routing and RAS connections.

To view the IP or IPX routing tables

1	Under IP Routing or IPX Routing, right-click Static Routes.

2	Click View IP routing table or View IPX routing table.

In addition to the routing table, you can see detail views of various router settings by right-clicking a component in the left window or an interface in the right window. The following table shows the detail views available in Routing and RAS Admin.

Component	Views
IP Routing/Summary	TCP/IP information
	Address translation table
	IP addresses
	IP routing table
	TCP connections
	UDP listener ports
OSPF	Area statistics
	Link state database
	Neighbor table
	Virtual interfaces
RIP for IP	RIP neighbors
IPX Routing/Summary	IPX global parameters
	IPX routing table
	IPX service table
Active Connections and Ports	Port Status
	Device statistics
	Network registration information


Adding and Deleting Packet Filters
Adding, Modifying, and Deleting Packet Filters

Filters are configured on an exception basis. That is, you can configure the filter to pass only the packets from the routes you list, or to pass everything except the packets for the routes you list.

To add, modify, or delete a packet filter

1	Under IP Routing or IPX Routing, click Summary.

2	Right-click the interface on which you want to create a filter, and then click Configure interface.

3	Click Input filters or Output filters.

4	In the Filters Configuration dialog box, click Add, Edit, or Delete to add, modify, or delete filters.


Adding Local Host Filters

A local host filter enables your computer to receive only traffic destined for the computer. A local host filter works by enabling users to access your computer, but not to route through your computer. After this filter is set, only traffic destined either for this host or to all hosts on the host's network will be allowed in on the interface.

To add local host filters

1	Under IP Routing, click Summary.

2	Right-click the interface over which you want to set the filter, then click Configure interface.

3	In the IP Configuration dialog box, click Input Filters.

4	In the IP Packet Filters Configuration dialog box, click Add.

You must create a set of five input filters and then select a Drop all except listed below option, as described in the table below:

Effects of Local Host Filter Options

Selecting this option	Has this effect
Allow packets coming directly to your computer	As an example, your router is configured with an IP address of 10.1.1.1 with a subnet mask of 255.255.255.255. To allow packets with a destination of your router, add a filter with the Destination IP address of 10.1.1.1, the Destination Subnet mask of 255.255.255.255, and select Any as the type of protocol.
Allow packets broadcast to the local subnet	The second filter enables you to receive packets that are going to the 10.1.x.x network. For this example, add a filter with the Destination IP address of 10.1.255.255, Destination Subnet mask of 255.255.255.255, and select Any as the type of protocol.
Allow packets going to subnetted networks	Set this filter to allow packets going to all subnets of the network. For this example, add a filter with the Destination IP address of 10.255.255.255, Destination Subnet mask of 255.255.255.255, and select Any as the type of protocol.
Allow packets broadcasting all 1's	For this example, add a filter with the Destination IP address of 255.255.255.255, Destination Subnet mask of 255.255.255.255, and select Any as the type of protocol.
Accept multicast packets	Set this filter to accept a limited form of mulitcast on the network 224.0.0.x. For this example, add a filter with the Destination IP address of 224.0.0.0, Destination Subnet mask of 255.255.255.0, and select Any as the type of protocol.


Adding PPTP Filters
Setting PPTP Filters

You can configure filters on an interface so that only PPTP traffic can use the interface. For example, a branch office connection can use PPTP and the Internet as a WAN.

For this type of configuration, you must set three input filters and three output filters on the interface over which you want to make the PPTP connection.

Note:	All six filters work together to complete a PPTP filter. The PPTP filter will not be secure unless all six filters are set correctly. The PPTP filtering option in the TCP/IP Advanced tab in Networks in Control Panel has no effect once Routing and Remote Access Service is installed.

PPTP uses TCP Port 1723 and IP Protocol ID 47. The process to set parameters when adding a filter includes the following procedures:

Select the interface over which you want to make the PPTP connection.

Add the Input filters.

Add the Output filters.

To select the interface over which you want to make the PPTP connection

1	Under IP Routing, click Summary.

2	Right-click the interface over which you want to make the PPTP connection, and then click Configure interface.

 Related Topics


Setting Input Filters

To add the first filter

1	In the IP Configuration dialog box, click Input Filters.

2	In the IP Packet Filters Configuration dialog box, click Add.

3	In the Add/Edit IP Filter dialog box , shown in the following figure, in the Protocol box, select Other.

4	In the Protocol box, type 47, and click OK.

To add the second filter

1	In the IP Packet Filters Configuration dialog box, click Add.

2	In the Add/Edit IP Filter dialog box , shown in the following figure, in the Protocol box, select TCP.

3	In the Source port box, type 1723; in the Destination port box, type 0, and then click OK.

To add the third filter

1	In the IP Packet Filters Configuration dialog box, click Add.

2	In the Add/Edit IP Filter dialog box , shown in the following figure, in the Protocol box, select TCP.

3	In the Source port box, type 0; in the Destination port box, type 1723, and then click OK..

4	In the IP Packet Filters Configuration dialog box, click Drop all except listed below, and then click OK.

 Related Topics


Setting Output Filters

Complete the same set of input filters procedures to add the three output filters.

To add the first filter

1	In the IP Configuration dialog box, click Output Filters.

2	In the IP Packet Filters Configuration dialog box, click Add.

3	In the Add/Edit IP Filter dialog box (see below), in the Protocol box, select Other.

4	In the Protocol box, type 47, and click OK.

To add the second filter

1	In the IP Packet Filters Configuration dialog box, click Add.

2	In the Add/Edit IP Filter dialog box , shown in the following figure, in the Protocol box, select TCP.

3	In the Source port box, type 1723; in the Destination port box, type 0, and then click OK.

To add the third filter

1	In the IP Packet Filters Configuration dialog box, click Add.

2	In the Add/Edit IP Filter dialog box , shown in the following figure, in the Protocol box, select TCP.

3	In the Source port box, type 0; in the Destination port box, type 1723, and then click OK.

4	In the IP Packet Filters Configuration dialog box, click Drop all except listed below, and then click OK.

 Related Topics


How to Setup a RAS Server
Setting Up a RAS Server

You must have selected to install a RAS Server when you installed Routing and Remote Access Service. If you did not select this option when you installed Routing and Remote Access Service then you must run mprsetup again to install it.

How to setup a RAS Server

1	In Network in Control Panel, from the Services tab select Routing and Remote Access Service and click Properties.

2	In the Remote Access Setup dialog box, click Add to add RAS-capable devices to your computer.

Note that you must install the device on your computer before you can add it to RAS. For instructions on installing a device, see the manufacturers documentation.

3	In the Remote Access Setup dialog box, select a port and then click Configure to enable the port to receive calls. You can also enable the port for routing if the RAS server will also be a router.

4	In the Remote Access Setup dialog box, select a port and then click Network to configure the transport protocols that clients can use to connect to this computer. You can also set the encryption to use when a client is trying to connect to the selected port, and enable Multilink for the port.

5	In the Remote Access Setup dialog box, click Continue.

After you have configured the RAS Server in Control Panel, start Routing and RAS Admin and view clients and devices by selecting Active Connections and Ports.

 Related Topics


Using RADIUS Authentication

If you install Remote Access Service (RAS), you can choose to use Remote Authentication Dial-In User Service (RADIUS) authentication instead of Windows NT authentication to authenticate remote clients.

1	In Network in Control Panel, from the Services tab select Routing and Remote Access Service and click Properties.

2	In the Routing and Remote Access Setup dialog box, click Network.

3	In the Network Configuration dialog box, in the Authentication provider box, click the RADIUS option and click Configure.

You can then select and configure RADIUS servers to use as your provider.


Creating a RAS IP Address Pool (allocate IP addresses for a RAS server)
Creating a RAS IP Address Pool

If you have clients or routers dialing in that need IP addresses assigned to them by the RAS Server, or a router dialing out, then you must configure a RAS IP address pool on the computer.

To create a RAS IP address pool

1	In Network in Control Panel, from the Services tab select Routing and Remote Access Service and click Properties.

2	In the Remote Access Setup dialog box, click Network.

3	In the Network Configuration dialog box, click Configure next to TCP/IP.

4	In the RAS Server TCP/IP Configuration dialog box, click the Use static address pool option, and type an IP address in the Address box.

5	A subnet mask for the address is automatically configured. To change the subnet mask, edit the IP address in the Mask box.

The range and number of addresses for the clients are automatically calculated.

 Related Topics


Granting Dial-In Permissions to RAS Clients

You must use User Manager for Domains to assign users in your domain dial-in permission. This functionality is not part of Routing and RAS Admin.

To assign users dial-in permission

1	Click the Start button, and then point to Programs.

2	Point to the Administrative Tools (Common) folder, and then click User Manager for Domains.

3	Click a user.
- or -
From the User menu, click New User.

4	In the User Properties dialog box, click Dialin.

5	In the Dialin Information dialog box, select the Grant dialin permission to user check box and click OK.

 Related Topics


Administering RAS Clients and RAS Servers

If you installed a RAS Server when you installed Routing and Remote Access Service, you can view and manage RAS clients that dial into your router. You can also administer down-level Windows NT RAS Servers and RAS clients on a Windows NT router.

You must use User Manager for Domains to add clients to your domain or server, and to grant users dial-in permissions.

To administer RAS clients and servers

1	In Routing and RAS Admin, click Active Connections and Ports.

The right window shows the RAS clients that are connected to your router as well as the currently available RAS lines.

2	Right-click a user to show status on the connection, or expand the user entry and right-click a device to get its status.

Note:	If you click a RAS server or client running on Windows NT version 4.0 or earlier, the Remote Access Admin tool appears and enables you to administer the down-level server.

 Related Topics


Enabling Tracing

To enable tracing, you must set the EnableConsoleTracing entry in the Registry to 1. This entry must be set to 1 before you start the router. You can find this key in the Registry using a Registry editor under:

HKEY_LOCAL_MACHINE\System

\CurrentControlSet

\Services

\Tracing

You can then enable tracing for each routing protocol by setting certain parameters in the Registry. You can enable and disable tracing for routing protocols while the router is running. Each routing protocol is capable of tracing and appears as a key (OSPF, RIPV2, and so on) under:

HKEY_LOCAL_MACHINE\System

\CurrentControlSet

\Services

\Tracing

To enable tracing, configure the following Registry entries under each protocol key:

Value	Data type	Default
EnableConsoleTracing	REG_DWORD	0x0
ConsoleTracingMask	REG_DWORD	0xFFFF0000
EnableFileTracing	REG_DWORD	0x0
FileDirectory	REG_EXPAND_SZ	Systemroot\tracing
FileTracingMask	REG_DWORD	0xFFFF0000
MaxFileSize	REG_DWORD	0x10000
EnableConsoleTracing
You enable console tracing (in a command prompt window on the router) by setting EnableConsoleTracing to 1.
The default value is 0.

ConsoleTracingMask
ConsoleTracingMask determines the extent of the tracing information displayed. A value of 0 indicates no information and 0xFFFFFFFF indicates maximum information. You can enable console tracing for multiple components at a time. Because there is only one console, each component is allocated a buffer inside the console.
You can change the buffer display by typing CTRL+TAB in the console window. If the tracing information scrolls too quickly in the console window, press the SPACE key to stop the scrolling and then type the SPACE key again to start scrolling.

EnableFileTracing
You can enable logging tracing information to a file by setting EnableFileTracing to 1.
The default value is 0.

FileDirectory
You can change the default location by setting the FileDirectory value to the path you want. The file name for the log file will be the name of the component for which tracing is enabled.
By default, the log files are placed in the Systemroot\tracing directory.

FileTracingMask
FileTracingMask determines the extent of the tracing information logged to the file.
The default value is 0xFFFF0000

MaxFileSize
You can change the size of the log file by setting MaxFileSize to different values.
The default value is 0x10000 (64K).

Note:	Tracing consumes system resources and should be used sparingly to help identify network problems. After the trace is captured or the problem is identified, you should immediately disable tracing.

The tracing information can be complex and very detailed. Most of the time this information will be useful only to Microsoft Product Support engineers or network administrators that are very experienced with Routing and Remote Access Service.


Quick Troubleshooting Checklist

This section steps through some basic routing configuration problems. It is intended to help you quickly identify a routing problem. The order of the checklists is from the most likely problem to the least likely problem.

If you cannot resolve your problem after completing these checks, you might have a problem with a specific routing protocol. See the "Troubleshooting RIP" and "Troubleshooting OSPF" sections for more information.

Is Routing and Remote Access Service running?

1	In Routing and RAS Admin, check to see whether the red stop light on the toolbar is lit. (If it is lit, the green stop light button will be gray.)

2	If the green stop light is lit and the red stop light button is gray, the router is not running. Click the green stop light to start the router.

3	If the router does not start, check the event log for error messages.

Is the router receiving routes?

In Routing and RAS Admin, select Static Routes under the IP Routing or IPX Routing folder, and then click View Routing Table on the Tools menu.

In the routing table, the Protocol column shows how the route was learned. If the Protocol column lists RIP or OSPF (or anything other than Local), then the router is receiving routes.

For more information on the routing table, see Understanding the Routing Table.

What protocols are you using and what interface are they enabled on?

In Routing and RAS Admin, expand IP Routing or IPX Routing in the left window to see what protocols are installed. Then select the protocol to see what interfaces are using the protocol.

For an interface running OSPF, you must verify that OSPF is enabled on that interface:

1	Select the interface, right-click, and choose Configure interface.

2	On the General tab, confirm that the Enable OSPF on this interface box is checked.

Is your IP configuration correct?

Check that you are using the correct subnet mask for your environment. Obtain this information by using ipconfig. To verify, you will have to try pinging your neighboring routers.

Note:	When routing in Windows NT, IP addresses for network cards must be on different subnets.

Is your default gateway correctly configured?

The backup gateway is used only if the primary gateway is down. The default gateway on additional network cards should be left blank.

Make sure all the following are true for your backup gateway:

The default gateway must be a router on a subnet that the computer running Windows NT is directly connected to. To check the default gateway, type ipconfig at a command prompt.

You must use only one default gateway per computer.

 To configure a backup gateway, use Network in Control Panel to configure the TCP/IP protocol: On the IP Address tab, click Advanced.


Using the Ping Command

If you are having connectivity problems, you can use the ping command to check your desired destination IP address and record the results.

You can:

Ping your computer (by address not hostname) to determine that TCP is functioning. (ping does not verify that your network card is functioning.)

Ping your default gateway or next hop router to determine whether the router is up.

Ping beyond the next hop router.

Some useful ping options:

n count

This parameter determines the number of echo requests to send. The default is 4 but can be increased with this parameter.

-l size

You can use this parameter to adjust the size of the ICMP PING packet. This is useful for Blackhole Router detection. [?]We may want to refer them to KnowledgeBase article Q159211 for an explanation of how to do this

-f

This parameter sets the Do Not Fragment bit on the ICMP PING Packet. This is used along with the -l parameter for Blackhole Router detection.

To check connectivity by using the ping command

1	At the Command Prompt, type ping and the IP address you want to reach.

A response of "Destination net unreachable" means there was no route to the destination. Check the routing table on the router listed in the Reply from address in the "Destination net unreachable" message. (For more information on the routing table, see Understanding the Routing Table.

A response of "Request timed out" means that there was no response to the ping in the default time period (about 1.5 seconds). The host might be down or there might not be a route back to you. To determine which is true, you can physically verify that the host is running, or check connectivity through another protocol. If the host is running, check for a return route by viewing the default gateway and local route table.

2	Use the tracert command to find at what router hop the ping is failing. To receive information about the tracert command, type tracert -?

The most common use of tracert is to type

tracert Computername [-d]

This returns a list of the routers it takes to get to Computername. Using the -d option with tracert makes the return faster because the computer does not try to resolve the names of the routers in the path.


Understanding the Routing Table

To troubleshoot routing, you must understand the routing table. Every computer that runs TCP/IP makes routing decisions that are controlled by the route table. To display the route table, in Routing and RAS Admin select Static Routes under the IP Routing or IPX Routing folder and then select View Routing Table on the Tools menu. See the following figure for an example of a route table. A description of each column follows the table.

Destination
This is the destination, host, subnet address, network address, or default gateway. The destination for a default route is 0.0.0.0.

Netmask
The netmask is used in conjunction with the destination to determine when a route will be used. For example, a host route will have a mask of 255.255.255.255, a default route will have a mask of  0.0.0.0, and a subnet or network route will have a mask somewhere in between these two extremes.

The mask of 255.255.255.255 means that only an exact match of the Destination will use this route. The mask of 0.0.0.0 means that any destination can use this route. When the mask is written in binary, a "1" is significant (must match) and a "0" means it does not need to match.

For another example, the destination 172.16.8.0 has a netmask of 255.255.248.0. This netmask means the first two octets must match exactly, the first 5 bits of the third octet must match (248=11111000) and the last octet does not matter. 8, the third octet of 172.16.8.0 equals 00001000 in binary. Without changing the first 5 bits (the masked off portion shown in bold), you can go up to 15, 00001111 in binary. Therefore, a route with destination of 172.16.8.0 with a mask of 255.255.248.0 will apply to all packets destined for 172.16.8.0 to 172.16.15.255.

Gateway
The IP address of the next router where this packet needs to be sent. The gateway must be directly reachable by this router. For instance, they must share a common LAN or WAN link. Note that the gateway address on a Point-to-Point link is configured but not used. The Interface is what is important on a Point-to-Point link.

Metric
The number of router hops to the destination or the cost of the route. This is used by the router to choose the best route.

Interface
The LAN or demand-dial interface to be used to reach the next router.

Protocol
Shows how the route was learned. If the Protocol column lists RIP or OSPF, (or anything other than Local) then the router is receiving routes.


Troubleshooting RIP for IP

The following steps are possible configuration problems with Internet Protocol Routing Information Protocol (IP RIP). All the options mentioned in these steps are configured per-interface by selecting RIP for IP and then selecting the interface, right-clicking, and then choosing Configure interface.

To check RIP configuration, check these things step by step:

1	If you have a mixed environment of RIP version 1 and RIP version 2, on the General tab ensure that RIP version 2 is using broadcast instead of multicast.

2	If you have selected the Enable authentication box on the General tab, make sure that the password in the Password box is the same as the password on the router receiving packets from this interface. By default, authentication is off.

3	On the Security tab, ensure that you are accepting routes and announcing routes correctly. By default, all routes are accepted and announced.

4	If host routes or default routes are not being propagated as you expect, change settings on the Advanced tab. By default, host and default routes are not sent or accepted.

5	If RIP does not learn routes over a demand-dial link, use multicast instead of broadcast. This is because demand-dial links can have endpoints on different subnets where broadcast RIP requests cannot be heard.

6	When using Auto-static RIP on a demand-dial interface, the first time you make a connection you must manually update routes. To do this, select Summary under the IP Routing folder, select the demand-dial interface, right-click, and then choose Update routes. This must also be done on the other router for the corresponding interface. The routes then appear under Static Routes.


Troubleshooting OSPF

When you use OSPF as your routing protocol, it is important to establish adjacencies. An adjacency is established when the Link State Databases of neighboring routers are fully synchronized. This section provides troubleshooting ideas for OSPF routers that are not able to establish an adjacency.

To check OSPF configuration, check these things step by step:

1	Ping the neighboring router to ensure basic network connectivity.

2	Windows NT OSPF routers have authentication enabled by default. The default password is 12345678. You should enable or disable passwords for an entire Area. On each router in an area, under IP Routing, right-click OSPF by Bay Networks and select Configure OSPF. On the Areas tab, select an area and click Configure. On the General tab, select the Enable clear-text password option.

3	Authentication must match between all neighboring OSPF routers. Therefore, within an area, any routers that are on the same network must use the same password. The password is configured on a per-interface basis by selecting OSPF by Bay Networks under IP Routing, right-clicking on an interface and selecting Configure interface. Configure the password on the General tab.

4	Be sure that the Hello and Dead Intervals match the Hello and Dead Intervals of neighboring OSPF routers. By default, the Hello interval is 10 seconds and the Dead interval is 40 seconds. These intervals are configured on a per-interface basis in the Advanced tab.

5	Be sure that area border routers (ABRs) are on the backbone: 0.0.0.0. Area border routers are routers that are part of two or more different OSPF areas. An ABR does not have to be physically on the backbone if a virtual link has been created that attaches it to the backbone. Virtual links are configured globally by using the Virtual Interfaces tab. When you configure the virtual interface, specify the router that is the endpoint of the virtual link by typing the router ID (not an IP address).

6	If the routers are on a nonbroadcast multiaccess (NBMA) network such as X.25 or Frame Relay, their neighbors must be manually configured because neighbors cannot found by using multicast. Neighbors are configured on a per-interface basis by using the Neighbors tab. Each neighbor must be listed by its IP interface address on the network.

7	If you have an NBMA network such as X.25 or Frame Relay that is in a hub and spoke configuration, be sure to set the Router Priority on spoke routers to 0 and on the hub router to 1 or greater. A router priority of 0 means that the router cannot become a Designated Router (DR). The hub router must be the DR since it is the only router that can communicate directly with all other routers. The router priority defaults to 1 and is set on a per-interface basis on the General tab.

8	On Broadcast (token ring, Ethernet, FDDI) or NBMA networks (X.25, Frame Relay), be sure that all routers do not have a priority of 0. At least one router needs a priority of 1 or greater to become the designated router.

9	Be sure neighboring routers are configured correctly with the same Area ID. Also, all routers must agree whether or not the area is a stub area.


Adding the OSPF Routing Protocol

1	In Routing and RAS Admin under IP Routing, right-click Summary, and select Add routing protocol.

2	In the Select Routing Protocol dialog box, click Open Shortest Path First (OSPF) by Bay Networks.

3	Complete any configuration dialog boxes for the protocol, and then click OK.

 Related Topics


Configuring OSPF

OSPF has two types of configuration associated with it: a per interface configuration and a global configuration. The global configuration is used for setting the router ID, event logging, Area information, virtual interface information, and route filters.

Configuring OSPF on an interface is used for setting the Area ID for the interface, cost, router priority, and passwords for the interface, and the type of interface. In addition, you can configure neighbors and set advanced features for the interface such as Hello and Dead intervals.

 Related Topics


To create an OSPF area
Creating and Configuring an OSPF Area

An OSPF area is defined as a list of address ranges. Interfaces on a router are assigned to an area depending on whether their addresses fall into one of the area's defining address ranges. Routers are viewed as belonging to multiple areas, depending on their attached interfaces' area membership.

The backbone area (0.0.0.0) is added to OSPF by default.

1	In Routing and RAS Admin under IP Routing, right-click OSPF by Bay Networks, and then select Configure OSPF.

2	Click the Areas tab, and then click Add to create a new area or click Configure to configure parameters for an area.

3	In the OSPF Area Configuration dialog box, on the General tab, type a 32-bit number that identifies the area in the Area ID box.

4	To enable passwords to be used on the area, select the Enable clear-text password check box.

Passwords are transmitted in clear text for purposes of identification, not security. When this option is selected:

All interfaces in the same area that are on the same network must use identical passwords.

Interfaces in the same area that are in different networks can have different passwords.

For instructions on how to configure passwords on an interface, see Setting Passwords on an Interface.

5	To mark the area as stub, select the Stub area check box. Note that the backbone cannot be configured as a stub area and virtual links cannot be configured through stub areas.

After marking the area as stub, you can configure the Stub metric and Import summary advertisements check boxes. For more information on these options, see the context sensitive help for the control within the dialog box.

 Related Topics


Setting Passwords on an Interface
Setting a Password on an Interface

By default, passwords are enabled and the password is "12345678." Because passwords are transmitted in clear text, this feature is for identification, not security.

To configure a password on an interface

1	In Routing and RAS Admin, select OSPF by Bay Networks, right-click an interface, and choose Configure interface.

2	On the General page, in the Password box, type a password.

Note:	All interfaces in the same area that are on the same network must use identical passwords.

Interfaces in the same area that are in different networks can have different passwords.

 Related Topics


Configuring Ranges for OSPF Areas

You can configure ranges on an area border router (ABR). Area ranges enable a router to minimize the number of summary advertisements that an ABR advertises.

By default, within an OSPF area there is a summary link advertisement for every network. An ABR can use ranges to summarize many networks into a single summary link advertisement. These summary advertisements describe a range of networks and enable all the networks within an area to be advertised as one network. One of the benefits of using ranges is to reduce the size of link state databases for routers that are outside the area, thus resulting in smaller routing tables.

Each address range consists of an IP network ID and subnet mask which describe the collection of IP addresses contained in the address range For example, Area 0.0.0.9 contains the four class C networks: 192.168.4.0, 192.168.5.0, 192.168.6.0, and 192.168.7.0. This range is defined as 192.168.4.0 mask 255.255.252.0. This area's four class C networks will now be advertised to other areas as a single route.

To configure ranges for OSPF areas

1	In Routing and RAS Admin under IP Routing, right-click OSPF by Bay Networks, and then select Configure OSPF.

2	Click the Areas tab, and then click Add.

3	In the OSPF Area Configuration dialog box, click the Ranges tab.

4	In the Address box, type the IP network ID for the range.

5	In the Mask box, type the associated mask for the range, and then click Add.

6	To delete a range, select it in the Ranges box and then click Remove.

7	After adding all the ranges for an area, click OK.

 Related Topics


Deleting an OSPF Area

1	In Routing and RAS Admin under IP Routing, right-click OSPF by Bay Networks, and then select Configure OSPF.

2	Click the Areas tab, and select an area to delete in the Areas box.

3	Click Delete and then click OK.

 Related Topics


Overview of Virtual Links

The backbone area in an OSPF network must be contiguous;. the backbone area 0.0.0.0 must not be broken up by non backbone areas. All other areas must be directly connected to the backbone.

Your network topology may be configured in such a way that access from an area to the backbone is not physically possible. In this case, you can configure a virtual link between the backbone and the unconnected area by creating a logical link across a common area between them. This common area is called a transit area. The transit area must have an area border router that is connected to the backbone. Virtual links cannot be configured across multiple transit areas.

In the previous example, Area 3 does not have a backbone router. Therefore, a virtual link is configured across the transit area of Area 2 between Area Border Router 2 and Windows NT Router 3. Area Border Router 2 and Windows NT Router 3 are known as virtual link neighbors.

When you want to create a virtual link, you must configure two virtual interfaces; for instance, one on Area Border Router 2 and one on Windows NT Router 3 in the previous picture.

A virtual link is not a physical link. It is a logical link that uses the least cost path over the transit area. An adjacency across the virtual link is formed and routing information is exchanged. Just as in physical adjacencies, the settings of the two virtual link routers (such as the Hello Interval and Dead Interval) must agree before an adjacency can be successfully established.

After a virtual link is established, OSPF treats two routers joined by a virtual link as if they were connected by an unnumbered point-to-point network that belongs to the backbone. Since the virtual link is considered as part of the backbone, you need to configure passwords on the virtual interfaces only if passwords have been enabled on the backbone. If they have, then the endpoints of the virtual link (the two virtual interfaces) must have the same password.

 Related Topics


Adding and Configuring Virtual Interfaces

To configure a virtual link, each router on either side of the virtual link must add and configure a virtual interface.

1	In Routing and RAS Admin under IP Routing, right-click OSPF by Bay Networks, and then select Configure OSPF.

2	Click the Virtual Interfaces tab, and click Add.

3	In the Transit area ID box, select the transit area over which you are connecting the virtual link. Since the router must be attached to this area, you can choose only from the areas already configured for the router. The backbone cannot be a transit area.

4	In the Virtual neighbor router ID box type the OSPF router ID of the router at the other endpoint of the virtual link (the virtual link neighbor). Recall that the router ID is the OSPF router ID, not necessarily the IP address of the router.

5	Enter the transmission related parameters - transit delay, retransmit interval, hello interval, and dead interval. The hello interval and dead interval must match between the two routers on each side of the virtual link for an adjacency to be established.

6	If the backbone area is configured to have a password, then type a password in the Password box. The passwords must be the same for the virtual interfaces that make up a virtual link.

7	Click OK to add the virtual interface.


Adding Interfaces to OSPF

You can add any LAN and WAN interfaces that have been created on the router to OSPF. All installed LAN cards, and WAN cards with drivers that make them appear as LAN cards (for example, Frame Relay), are automatically created in Routing and RAS Admin during Setup. You can add other types of WAN ports (for example, modems or ISDN) to OSPF, but you must first add them to the router as demand-dial interfaces.

If you are using OSPF over WAN connections, they must be lines that are permanently connected and not lines that are connecting and disconnecting.

To create a WAN interface, run the Demand-Dial Wizard

In Routing and RAS Admin, right-click LAN and Demand Dial Interfaces, check Use demand dial wizard, and then select Add interface.

After adding the WAN interface, configure it for persistent connections

1	In Routing and RAS Admin select LAN and Demand Dial Interfaces, right-click the WAN interface you just created and select Configure interface.

2	Click the Dialing tab, and then click the Persistent connection option.

To add an interface to OSPF

1	In Routing and RAS Admin under IP Routing, right-click OSPF by Bay Networks, and then select Add interface.

2	In the Interfaces box, select the interface you want to add and click OK.

You can then configure settings for the interface. For more information, see Configuring Interfaces.


Configuring Interfaces

1	In Routing and RAS Admin, select OSPF by Bay Networks, right-click an interface, and choose Configure interface.

Note:	If the interface has multiple IP addresses configured on it, then you will see an IP Address box on the General tab. Configure OSPF parameters for each IP address on the interface.

2	On the General tab, click the Enable OSPF on this interface check box.

3	In the Area ID box, select the ID of the area to which the interface belongs.

4	In the Router priority box, select the priority of the router over this interface. A priority of 0 means that the router will not participate in the Designated Router Election.

5	In the Cost box, select how expensive it is to send a packet over the interface. A larger cost means the interface will not be used as much as other interfaces with a lower cost.

6	In the Password box, if the area to which the interface belongs is enabled for passwords, type a password in the box.

For more information, see Setting Passwords on an Interface.

7	In the Type box, choose the type of the interface.

8	Use the Neighbors and Advanced tabs to configure neighbors for the interface and set advanced features such as Hello and Dead intervals. Note: neighbors are configured for NBMA interfaces only.

For more information, see Configuring OSPF Neighbors and Configuring the Hello and Dead Intervals.


Configuring the Hello and Dead Intervals

You can configure advanced features such as hello and dead intervals for an interface.

To configure hello and dead intervals on an interface

1	In Routing and RAS Admin, select OSPF by Bay Networks, right-click an interface, and choose Configure interface.

2	Click the Advanced tab.

3	In the Hello interval box, type the number of seconds between transmissions of hello packets by the router on the interface. This setting must be the same for all routers attached to a common network.

4	In the Dead interval box, type the number of seconds before a silent remote router is declared down.

Note:	This setting should be a multiple of the hello interval (commonly 4). This value must be the same for all routers attached to a common network.

5	Configure any other features on the Advanced tab and then click OK.


Configuring OSPF Neighbors

You must configure the IP addresses of neighboring routers in a non-broadcast multiple access (NBMA) network (such as an X.25 or Frame Relay configuration). Note that you configure the type of network you have in the OSPF Interface Configuration dialog box on the General tab.

To add OSPF neighbors

1	In Routing and RAS Admin, select OSPF by Bay Networks, right-click an interface, and choose Configure interface.

2	In the OSPF Interface Configuration dialog box, click the Neighbors tab.

3	In the Address box, type the IP interface address (not the router ID) of a router attached to the non-broadcast network.

4	In the Priority box, select the priority for the neighbor. This is used to determine the neighbors' eligibility to become Designated Router. When an interface to a non-broadcast network comes up, the router sends Hello packets only to those neighbors eligible to become Designated Router, until the identity of the Designated Router is discovered.

5	Click Add to add the neighbor.

6	Repeat these steps until you have added all routers attached to the non-broadcast network, and then click OK.

To remove OSPF neighbors

1	In the NBMA neighbors box, select the neighbor you want to delete and click Remove.

2	Click OK.


Types of OSPF Routers

When you split an Autonomous System into OSPF areas, the OSPF routers are divided into four categories:

Internal routers: A router with all the networks that it is connected to belonging in the same area.

Area border routers: A router that is attached to multiple areas.

Backbone routers: A router that is connected to the backbone. This includes routers that are connected to more than one area (area border routers). However, backbone routers do not have to be area border routers. Routers that have all networks connected to the backbone are internal routers.

AS boundary routers: A router that exchanges routing information with routers that belong to other Autonomous Systems. The AS boundary router then advertises external routes throughout the Autonomous System. AS boundary routers can be internal or area border routers, and may or may not be connected to the backbone.


Enabling Auto-static Update Mode

When you set auto-static update mode for RIP for IP, the router will not send out any periodic route announcements. Instead, the router sends out manual requests to remote routers for their routing tables. The routes that are received from the remote router are stored as Auto-static routes on the local router.

After enabling auto-static update mode on an interface, you must manually request routes.

To enable auto-static update mode

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to set auto-static update mode, and click Configure interface.

3	On the General tab, in the Operation mode box, select Auto-static update mode.

 Related Topics


Performing Auto-static Updates

A router can import routes from another router and save them as auto-static routes. Auto-static routes do not expire and must be explicitly deleted if they are not required. In this respect, they are similar to static routes. To enable auto-static updates on an interface you must have at least one routing protocol enabled on the interface that is capable of performing auto-static updates. On Windows NT routers, only RIP for IP supports auto-static update mode; OSPF does not.

Note:	When an auto-static update is performed, the existing auto-static routes for this interface are deleted before the update is requested from the other router. If there is no response to the request, then the router cannot replace the routes it has deleted. This might lead to a loss of connectivity to remote networks.

Before you can perform auto-static updates on an interface, you must have enabled auto-static update mode on that interface. For more information, see Enabling Auto-static Update Mode.

To perform auto-static updates

1	Under IP Routing, click Summary.

2	Right-click the interface on which you want to perform auto-static updates and click Update routes.

The process takes about 10-30 seconds.


Setting Timers for Periodic Update Mode

You can configure the periodic route announcement interval, the route expiration interval, and the route removal interval used by RIP for IP when operating in Periodic update mode. The values are configured separately for each interface. The default values are 30, 180, and 120 seconds, respectively.

To configure interval values

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to set the timer, and then click Configure interface.

3	On the Advanced tab, set the timer interval values as needed. The values entered are in seconds.


Adding Route Filters

RIP for IP route announcements packets can be filtered to include or exclude ranges of routes. You can create a per-interface list of range filters to be applied to incoming or outgoing route announcements.

To add a route filter for RIP for IP route announcements

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to set route filters, and click Configure interface.

3	On the Security tab, you can select two modes in which to set filters: when accepting routes or when announcing routes. In the drop-down box at the top of the page, select When accepting routes for filters to be applied to incoming RIP for IP announcement packets. Select When announcing routes for filters to be applied to outgoing RIP for IP announcement packets.

4	In the Range from box, type the IP address of the beginning of the range for the route filter.

5	In the to box, type the IP address of the end of the range for the route filter.

6	Click Add to add the filter.

7	Select the action to be applied to the ranges specified in the Ranges box. You can select to process only the routes listed in the Ranges box or choose to discard all the routes listed in the Ranges box.

8	Click OK when you are finished adding route filters.


Adding Peer Filters

You can set RIP for IP filters to select the peer routers from which you want to receive or discard route announcements. The set of peer routers is global and applies to all interfaces. The default action is to accept route announcements from all routers.

To add a peer filter

1	Under IP Routing, right-click RIP for Internet Protocol, and select Configure RIP.

2	On the Security tab, in the Router box, type the IP address of the router whose announcements are to be filtered.

3	Click Add.

4	Select how to process announcements from the set of peer routers listed in the Routers box. Note that this action applies to all the peer routers; you cannot set the action per router.


Enabling Authentication

You can enable authentication for RIP for IP and use simple passwords. These passwords can be up to 16 characters long and are set on a per-interface basis. Authentication is not enabled by default.

To set authentication

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to set authentication, and then click Configure interface.

3	On the General tab, click the Enable Authentication check box, and then type a password in the Password box and click OK.


Setting Split Horizon Processing

You can enable or disable split horizon perinterface. This is enabled by default on all interfaces that have enabled RIP for IP.

To enable or disable split horizon

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to change split horizon processing, and then click Configure interface.

3	On the Advanced tab, select or click to clear the Enable split-horizon processing check box and click OK.


Setting Poison Reverse Processing

You can enable or disable poison reverse per interface. This is enabled by default on all interfaces that have enabled RIP for IP.

To enable or disable poison reverse

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to change split horizon processing, and then click Configure interface.

3	On the Advanced tab, enable or disable the Enable poison-reverse processing check box and click OK.


Adding a Unicast Neighbor

RIP for IP route announcements are normally broadcast or multicast. RIP for IP allows you create a per-interface list of neighbor routers to which route announcements are sent as unicast. This option is for non-broadcast media and point-to-point links.

To add a unicast neighbor

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to set unicast neighbors,and click Configure interface.

3	On the Neighbors tab, in the Neighbor box, type the IP address of the unicast neighbor.

4	Click Add to add the neighbor.

5	Select to use the neighbor list in addition to using broadcast or multicast, or select to use only the neighbor list. Note that when you select one of these options it applies to all of the unicast neighbors.


Overriding Non-RIP Routes with RIP

Non-RIP routes can be overridden with RIP routes on a per-interface basis. This is disabled by default on all interfaces that have enabled RIP for IP.

To enable RIP route override

1	Under IP Routing, select RIP for Internet Protocol.

2	Right-click the interface on which you want to change RIP route override, and then click Configure interface.

3	On the Advanced tab, select the Override non-RIP routes with RIP-learnt routes check box and click OK.


Ignoring Incoming Route Announcements and Requests

You can configure RIP for IP to ignore incoming route announcements. In this mode, RIP for IP performs periodic route announcements only if configured to do so. RIP for IP will not accept route announcements or requests for routes from other routers on that interface.

To enable RIP for IP to ignore incoming packets

1	Under IP Routing, click RIP for Internet Protocol.

2	Right-click the interface on which you want to set RIP for IP to ignore incoming packets, and then click Configure interface.

3	On the General tab, in the Protocol for incoming packets box, select Ignore incoming packets and click OK.


Enabling Silent Mode

You can configure RIP for IP to run in silent mode. In silent mode, RIP for IP will only listen to route announcements from other routes. RIP for IP will not send route announcements or respond to requests from other routers in this mode.

To enable Silent RIP mode

1	Under IP Routing, click RIP for Internet Protocol.

2	Right-click the interface on which you want to set silent RIP mode, and then click Configure interface.

3	On the General tab, in the Protocol for outgoing packets box, select Silent RIP and click OK.


Connecting Networks Across the Internet using PPTP

You can configure a Windows NT router to enable Dial-Up Networking clients and other Windows NT routers to connect across the Internet using PPTP in order to gain access to your network. To connect networks across the Internet using PPTP, you must install and configure PPTP and the Routing and Remote Access Service on the Windows NT routers in each that are connected to the Internet:

Configure PPTP with as many VPN devices as you need for dial-in clients. For more information, see Adding VPN Devices to PPTP.

Configure the Routing and Remote Access Service to add the new PPTP devices and enable the devices for routing, dial-in connections, or both. Note that for efficiency reasons you should select only as many devices for router connections as you need. For more information, see Adding and Configuring Devices for Routing.

Note:	PPTP isolates your internal addressing scheme from that of the Internet; however, the two or more networks you are connecting using PPTP tunnels cannot have conflicting address spaces.

After you have configured PPTP and the Routing and Remote Access Service, you must establish a connection to an ISP in order to connect to the Internet. You can connect to the Internet using demand dial, WAN, or LAN connections. For more information, see Connecting Your Internal Network to the Internet.

Finally, after you have PPTP and Internet connectivity established, you must configure the following in Routing and RAS Admin:

Add a demand-dial interface to connect to the remote router. If you are using demand-dial to connect to the Internet, you must add a demand-dial interface for that connection as well. For more information, see Adding a Demand-Dial Interface.

If both Windows NT routers that are connected to the Internet support mutual authentication and strong encryption, enable these options on the demand-dial interface. For more information, see Authenticating Your Routers and Sending Encrypted Data Over the Internet.

You can route over PPTP tunnels by using static routes or dynamic routing protocols. For more information, see Routing Over PPTP Tunnels.

For maximum security, you should set a filter to ignore all traffic except PPTP on the interface. For more information, see Setting PPTP Filters.

Remember to perform these configuration steps on the Windows NT router at the other end of the tunnel.

To ensure that the router uses the tunneled connection, at a command prompt window type tracert and an address on the remote network. If the packet is taking the tunneled path, you will see one hop across the Internet, with your PPTP routers at either end.


Adding and Configuring Devices for Routing
Adding and Configuring Devices (Ports) for Routing

1	In Network in Control Panel, click the Services tab.

2	Select Routing and Remote Access Service and click Properties.

3	To add a device, in the Remote Access Setup dialog box, click Add, and then select a device in the Add RAS Device dialog box.

4	To configure a device for routing, in the Remote Access Setup dialog box, select a device and click Configure.

In the Configure Port Usage box, select the Dial out and receive calls as a demand dial router check box, and click OK.

5	Click OK when you are finished adding and configuring devices for routing.


Adding VPN Devices to PPTP

1	In Network in Control Panel, click the Protocols tab.

2	Select Point to Point Tunneling Protocol and click Properties.

3	In the PPTP Configuration dialog box, select the number of connections (Virtual Private Networks) that you want available to PPTP.

RAS setup will start and add the PPTP protocol to Routing and Remote Access Service. Choose the port on which you want to install the PPTP protocol and click OK.

4	You must restart your computer for the PPTP configuration to take effect.

 Related Topics


Routing Over PPTP Tunnels

You can use dynamic routing protocols or static routes to route over PPTP tunnels. When making a decision, you must consider what routing protocols are running at either end of the tunnel; and whether or not the tunnel across the Internet uses a demand-dial media such as ISDN that incurs usage-based charging.

If you are running over a demand-dialed media and want to limit use-based charges, you can use static routes or use RIP for IP or RIP for IPX in Auto-static update mode. For more information, see Enabling Auto-static Update Mode or Adding Static Routes

If you are running over a media which does not charge by use, you can configure the PPTP interface to be a persistent interface. When you use a persistent interface, you can use the routing protocols OSPF and RIP. For more information, see Adding Interfaces to OSPF.


Connecting Your Internal Network to the Internet

To connect your local network to the Internet, you must contact an ISP and obtain either a dedicated, leased line or a demand-dial account that will enable your Windows NT router to send and receive packets over the Internet.

What do you want to do?

 I want to use a modem to connect my internal network to the Internet

 I want to use ISDN devices to connect my internal network to the Internet

 I want to use PPTP to connect my internal network to the Internet

 I want to use a T1 line or Frame Relay to connect my internal network to the Internet

 I want to configure my routers to authenticate remote routers

 I want to send encrypted data over the Internet


Using ISDN Devices to Connect to the Internet

After creating the interface you must add a default network route (0.0.0.0 network) over this interface.

1	Install the ISDN hardware in your computer.

2	Add the ISDN adapter to your computer by using the Adapters tab in Network in Control Panel.

After the ISDN adapter is added, you will be prompted to configure the adapter for Routing and Remote Access.

3	In the Remote Access Setup dialog box, click Add.

4	In the Add RAS Device dialog box, select the device you want in the RAS Capable Devices list, and then click OK.

5	In the Remote Access Setup dialog box, select the ISDN device and click Configure.

6	In the Configure Port Usage dialog box, select the Dial out and receive calls as a demand dial router check box and click OK.

7	In the Remote Access Setup dialog box, click OK to finish Setup.

8	After rebooting, start Routing and RAS Admin and add a demand-dial interface and configure it to use the ISDN device to dial into the ISP. For more information, see Adding a Demand-Dial Interface.

9	Add a default static route.


Using a Modem to Connect to the Internet

1	Install the modem hardware on your computer.

2	In Control Panel, double-click Modems.

3	On the General tab, click Add.

Follow the steps in the Install New Modem wizard.

4	In the Remote Access Setup dialog box, click Add.

5	In the Add RAS Device dialog box, select the device you want in the RAS Capable Devices list, and then click OK.

6	In the Remote Access Setup dialog box, select the modem and click Configure.

7	In the Configure Port Usage dialog box, select the Dial out and receive calls as a demand dial router check box and click OK.

8	In the Remote Access Setup dialog box, click OK to finish Setup.

9	After rebooting, start Routing and RAS Admin and add a demand-dial interface and configure it to use the modem to dial into the ISP.

 Related Topics


Using a T1 Line or Frame Relay to Connect to the Internet.
Using a T1 Line or Frame Relay to Connect to the Internet

1	Install a T1 or Frame Relay network card in your computer.

2	Add the adapter to your computer by using the Adapters tab in Network in Control Panel.

After the adapter is added, you will be prompted to configure the adapter for Routing and Remote Access.

3	In the Remote Access Setup dialog box, click Add.

4	In the Add RAS Device dialog box, select the device you want in the RAS Capable Devices list, and then click OK.

5	In the Remote Access Setup dialog box, select the device and click Configure.

6	In the Configure Port Usage dialog box, select the Dial out and receive calls as a demand dial router check box and click OK.

7	In the Remote Access Setup dialog box, click OK to finish Setup.

8	After rebooting, start Routing and RAS Admin. The WAN card automatically appears as an interface in Routing and RAS Admin.

9	Add a default static route.


 Authenticating Your Routers

If you are using demand-dial connections (particularly with PPTP tunnels across the Internet), you can configure your Windows NT router to authenticate the remote router as well as enable the remote router to authenticate you. You must create an account for the remote router on your computer or domain (depending on your network security policy) so that the remote router can be authenticated.

To authenticate a router

1	Create a user account with dial-in permissions. For more information, see Granting Dial-In Permissions to RAS Clients.

2	In Routing and RAS Admin, select LAN and Demand Dial Interfaces.

3	Right-click the interface and select Configure interface.

4	On the Security tab, click the Use two-way authentication check box.

Note:	If you are using PPTP connections across the Internet you should install the Password Filtering support that is part of Windows NT version 4.0 Service Pack 3. This support enables Windows NT to enforce non-trivial passwords for all users, thus making it difficult for hackers on the Internet to guess passwords and gain access to your network. Password Filtering can be installed using instructions in README.TXT that comes with Windows NT Service Pack 3.


Sending Encrypted Data Over the Internet

You can enable strong data encryption on a demand-dial interface to ensure that the demand-dial connection succeeds only if the remote router also supports strong data encryption. This feature is useful if you have 128-bit encryption installed on your router and you want to be sure that 128-bit encryption is forced on every connection.

To require data encryption

1	In Routing and RAS Admin, select LAN and Demand Dial Interfaces.

2	Right-click the interface and select Configure interface.

3	On the Security tab, select the Require data encryption check box, and then click the Require strong data encryption check box and click OK.


Using PPTP to Connect to the Internet

You can configure a Windows NT router to enable Dial-Up Networking clients and other Windows NT routers to connect across the Internet using PPTP in order to gain access to your network. To connect networks across the Internet using PPTP you must install and configure PPTP, and the Routing and Remote Access Service on the Windows NT routers in each that are connected to the Internet.

 Related Topics


Using Autostatic Updates
Using Auto-static Updates

Routing and Remote Access Service includes support for Auto-static updates. Auto-static updates are supported in RIP, but are not available for use with OSPF. When you configure an interface to use the Auto-static update mode, the router sends a request and then puts the responses in a dynamic list that is kept if the interface goes down.

If you have many static routes to add, you can configure RIP for IP and IPX and SAP for IPX on an interface to use Auto-static updates.

You can also schedule Auto-static updates by using the routemon and at commands from a command-prompt window. For more information about scheduling Auto-static updates, see Appendix B "Command-Line Interface."

 Related Topics


Click this check box to enable packet filtering over IP connections.

Packet filtering adds security, but can reduce performance. If you select the Enable packet filtering check box, click an interface and configure the input and output filters for that interface.


Select this option to disable event logs in the Event Viewer administrative tool.


Select this option to log only errors in the Event Viewer administrative tool.


Select this option to log errors and warnings in the Event Viewer administrative tool.


Select this option to log the maximum amount of information in the Event Viewer administrative tool.


Shows the preference level of the routing protocols. Therefore, if two routes exist to same destination, then the route learned by the protocol at the smaller number is preferred over the route learned by the protocol at the higher number.


Select a protocol and then click to raise its preference level.


Select a protocol and then click to reduce its preference level.


The DHCP Servers list displays the DHCP server addresses on the network.

The router can act as a DHCP relay agent by getting DHCP requests and sending replies to DHCP servers specified in this list. You must add at least one address to be a relay agent.

You must select the Relay DHCP packets check box on at least one interface before the relay agent works.


Type an IP address in the Server box and then click to add a DHCP server address.


Select a DHCP server address and then click to remove it.


Type the IP address of the DHCP server you want to add and then click Add.


Select this check box to relay DHCP packets across this interface. This enables requests and reply packets to be sent out over this interface.

After you select this option, you must configure the DHCP server addresses in the Configure DHCP Relay Agent global dialog box.


Type a value for the maximum distance the packet will travel. This is the limit on how far the DHCP packets will travel from the router that sends the DHCP packet. The default is 4 hops. The maximum possible value is 16 hops.


Type the number of seconds the relay agent waits before forwarding DHCP messages. The relay agent then forwards the messages after the specified time.

This option is useful in the case where you want a local DHCP server to respond first, but if the local DHCP server does not respond, you want to forward messages to a remote DHCP server.

The default is 4 seconds.


Type the 32-bit number - in dotted decimal notation (for example, 172.16.1.1) - that uniquely identifies the router in the network. This number must be unique. One way to make sure it is unique is to choose the largest or the smallest IP address assigned to one of the interfaces on the computer. (The ipconfig command shows you the IP addresses of the interfaces.)


Select this check box to enable the router to act as an AS (Autonomous System) boundary router. An AS boundary router exchanges routing information with routers that belong to other Autonomous Systems. The AS boundary router then advertises external routes throughout the Autonomous System. AS boundary routers can be internal or area border routers, and might be connected to the backbone.

When enabled, you can configure external routes and protocols on the External Routing tab.


Select this option to disable OSPF event logs in the Event Viewer administrative tool.


Select this option to log OSPF errors in the Event Viewer administrative tool.


Select this option to log OSPF errors and warnings in the Event Viewer administrative tool.


Select this option to log all OSPF information in the Event Viewer administrative tool.


An OSPF area is a way of subdividing the network. An area is similar in concept to a Windows NT domain.

A router can have many areas configured. An interface on the router must belong to one area.

To use the OSPF routing protocol, you must have at least one area configured. If you have more than one area configured, you must also configure a backbone area. The area number of 0.0.0.0 is reserved for the backbone area. You can configure a total of 16 areas.

Types of OSPF Routers


Click to add a new area.


Click to configure ranges for an area.


Select an area and then click to delete it from the OSPF configuration.


Type an ID for the area. This is a 32-bit number that identifies the area. The area ID does not have to coincide with an IP address or IP network ID. The Area ID of 0.0.0.0 is reserved for the backbone. If the area represents a subnetted network, the IP network number of the subnetted network can be used for the Area ID for administrative convenience.


Select this check box to require passwords for the area. If you require passwords for an area, then all interfaces on that area must have a password. See the following notes about passwords:

All interfaces in the same area that are on the same network must use identical passwords.

Interfaces in the same area that are in different networks can have different passwords.

By default, passwords are enabled and the password is "12345678."

Passwords are transmitted in clear text so this feature is for identification, not security.

To configure passwords on an interface

1	Click OSPF by Bay Networks.

2	Right-click an interface, and click Configure interface.

3	On the General tab, set a password in the Password box.


Select this check box to mark the area as a stub area.

AS (Autonomous System) external advertisements are not flooded into or through stub areas. Routing to AS external destinations in these areas is based only on a default summary route. This reduces the topological database size and therefore the memory requirements for a stub area's internal routers.

The backbone cannot be configured as a stub area. Virtual links cannot be configured through stub areas.

For more information about configuring stub areas, refer to RFC 1583, OSPF Version 2.


If the area has been configured as a stub area, and the router itself is an area border router, then the stub metric indicates the cost of the default summary link that the router advertises into the area.

Enter the cost of the default summary link that the router will advertise into the stub area.


Select this check box to import AS interarea summary routes into this stub area. By default, this is disabled; therefore, all non-intraarea routes are routed based on a default route.


Indicates the address and mask pair that define a range of addresses belonging to the area.


To add a range, type address and mask in the Range box, and then click Add.


To remove a range, select it in the Ranges box and click Remove.


Type the IP address for the range.


Type the mask for the range.


An OSPF interface is the connection between a router and a network. A virtual interface is the connection between an endpoint and the area it travels. After you create a virtual interface, it appears as any other interface to the router.

Virtual interfaces are used when a physical connection is not possible. For example, a router might need to be connected to the backbone, but be in a location to which it cannot physically connect. In this case, you instead create a virtual interface to connect to the endpoint (the router) on the backbone.


Click to add a virtual interface.


Select an interface and click to configure it.


Select an interface and click to delete it.


Select the area to which this router is connected. Do not select the backbone.


Type the IP address of the router at the endpoint.


Select the estimated number of seconds that it takes to transmit a description of the virtual interface's links (the link state update packet) over this interface.


Select the number of seconds between link state advertisement transmissions. This number should be significantly larger than the expected round-trip delay between any two routers on the attached network. Because this can be difficult to estimate for a virtual link, it is better to err on the side of making it too large.


Select the length of time, in seconds, between Hello packets that are sent out on this interface.


Select the number of seconds a router's neighbors will wait after they cease to hear the router's Hello packets before they declare that the router is down.


Type the password for the virtual interface.

The two interfaces comprising a virtual link must have the same password.


Select this option and then select the non-OSPF protocols you do not want to use.

Note:	You can do external routing only when you have selected the Enable autonomous system boundary router check box in the General tab.


Select this option and then select the non-OSPF protocols you want to use.

Note:	You can do external routing only when you have selected the Enable autonomous system boundary router check box in the General tab.


Shows the list of non-OSPF routing protocols you can use for external routing.


Click to set filters for external routes.


Select this check box to exclude the external routes that are listed in the Routes box.

By default, all external routes are included.


Select this check box to route to only the external routes listed in the Routes box.


Displays a list of external routes to use as a filter.


Type an IP address in the Address box and then click to add an external route.


Select a route in the Routes box and then click to remove it.


Type an IP address and then type a subnet mask in the Mask box.


Type a subnet mask and then click Add to add the route to the Routes box.


Triggered updates are sent when the entries in a router's routing table have changed. The default is 5 seconds.

Choose the interval between triggered updates. A longer delay enables more changes to the routing table to be collected into one triggered update.


Select this option to disable RIP for IP event logs in the Event Viewer administrative tool.


Select this option to log RIP for IP errors in the Event Viewer administrative tool.


Select this option to log RIP for IP errors and warnings in the Event Viewer administrative tool.


Select this option to log all RIP for IP information in the Event Viewer administrative tool.


By default, announcements from all routers are processed. If you want to select particular routers from which to discard or receive packets, check the corresponding options below and enter the IP addresses.


Select this option to accept announcements coming from only those routers listed below.

Any announcements from routers that are not in the list will be discarded.

This option is useful if you want to send packets only to routers you know are secure on your network.


Select this option to ignore announcements coming from those routers listed below. Announcements from all other routers will be processed.

This option is useful if you want to prevent malfunctioning routers from interfering with this router.


Displays the addresses of routers that you have added.


Type an IP address in the Router box and click Add.


Double-click the router address in the Routers list, edit it, and then click Replace.


Double-click the router address in the Routers list and click Delete.


Type the IP address of the router and then click Add.


You can choose one of two operation modes: auto-static update mode or periodic update mode.

Auto-static update mode sends out a router's routing table only when other routers request an update. Routes learned over RIP while in auto-static mode are marked as static routes when they are stored in the routing table. If you start and stop the router or if RIP is disabled, these routes remain in the routing table until they are manually deleted.

This is the default for demand-dial interfaces.

Periodic update mode sends out a router's routing table every few seconds, as specified in the Periodic announcement timer option in the Advanced tab. Routes learned over RIP while in periodic mode are marked as RIP routes and are deleted if the router is stopped and restarted.

This is the default for LAN interfaces.


Choose one of the following protocols for sending packets out over the interface:

RIP version 1 broadcast: Broadcasts only RIP version 1 announcements.

RIP version 2 broadcast: Broadcasts RIP version 2 and RIP version 1 packets. Select this option if you have a mixed environment with RIP versions 1 and 2.

RIP version 2 multicast: Broadcasts standard RIP version 2 multicast. Select this option only if all the adjacent RIP routers on the network connected to this interface are also RIP version 2 routers. A RIP version 1 router will not process a RIP version 2 multicast announcement.

Silent RIP: Disables outgoing packets (that is, RIP announcements) on this interface. In silent mode, the computer listens to RIP broadcasts and updates its route table but does not advertise its own routes.


Choose one of the following protocols for RIP packets received from other routers:

Ignore incoming packets: Ignores packets. Select this option if you want a router that only announces routes.

RIP version 1 and 2: Accepts packets of both types.

RIP version 1 only: Accepts only RIP version 1 packets.

RIP version 2 only: Accepts only RIP version 2 packets.


This is the cost associated with sending packets over this interface. When routes are added to the routing table, this number is added to the hop count as advertised in the RIP message. By default, this value is 1 to indicate the additional hop as created by the receiving router. Set this cost higher if you want to associate a higher cost with the route - for instance, if this is a heavily trafficked route that you do not want used unless other routes are unavailable. However, the accumulated costs/hops for the farthest nodes on the IP internetwork must not exceed 15.


Specify a tag number if you want all packets sent over this interface to include this tag in the RIP packets.


Select this option if you want to specify a clear-text password to use over this interface. This means that all incoming and outgoing RIP packets must contain the same clear-text password. Therefore, any routers connected to this interface need to have this password enabled.

This option is a form of identification. It is not a security option.


Type a password between 8 and 16 characters long. This password will be sent as clear text in the RIP v2 message for authentication between adjacent RIP v2 routers.


Configure neighbors when you want to specifically target a router.

Select this option to ignore all neighbors configured in the list and to send RIP announcements by using the method configured on the General tab.


Select this option if you want to send packets to specific neighboring routers in addition to broadcasting or multicasting RIP announcements. Packets sent to the configured neighbors are unicast.


Select this option to send RIP packets to only the configured neighbor routers. They are not broadcast or multicast even if you have selected the broadcast or multicast RIP protocol in the General tab.

This option is useful if you have nonbroadcast networks and want to enable RIP between specific routers.


Shows the list of configured neighbor IP addresses.


Type the IP address of the neighboring router in the Neighbor box and then click Add.


Double-click an IP address in the Neighbors list, edit it, and then click Replace.


Double-click an IP address in the Neighbors list and then click Delete.


Type the IP address of the neighbor.


You can set security for how you accept routes and how you announce routes. All the controls in this property page are specific to the option you have selected in this box. To set security for accepting routes, select When accepting routes and configure the security controls. Then, select When announcing routes and reconfigure the options for that mode.


When accepting routes:

Select this option if you want the router to look at every route entry in an incoming RIP packet to determine whether to update its routing table with this route.

When announcing routes:

Select this option if you want the router to include all entries in its routing table in outgoing RIP packets.


When accepting routes:

Select this option if you want the router to look at each route entry in an incoming RIP packet and process it only if the route falls between one of the configured ranges.

When announcing routes:

Select this option if you want the router to include a route in the outgoing RIP packet only if it falls into one of the configured ranges.


When accepting routes:

Select this option if you want the router to look at each route entry in an incoming RIP packet and discard it if it falls between one of the configured ranges.

When announcing routes:

Select this option if you want the router to exclude a route from the outgoing RIP packet if it falls into one of the configured ranges.


When accepting routes:

The list used to filter the route entries in the incoming RIP packets.

When announcing routes:

The list used to filter the route entries from the routing table.


To add a new range, type IP addresses in the Range from and Range to boxes and then click Add.


To replace an existing range, double-click a range, edit it, and then click Replace.


To delete a range, double-click the range and click Delete.


Type the IP address for the lower end of the range, for example 100.1.1.1.


Type the IP address for the higher end of the range, for example 110.1.1.1.


Select the number of seconds between periodic updates. The default value is 30 seconds, which means the entire routing table is updated every 30 seconds. This value can be set anywhere between 15 seconds and 86,400 seconds (24 hours).

Note:	This control is valid only if you have selected Periodic update mode in the General tab.


Select the lifetime (in seconds) of a route that is learned through RIP. This number determines how long to keep a route in the routing table. The default value is 180 seconds. Valid settings are from 15 seconds to 259,200 seconds (72 hours).

If a route has not been updated by the time set here, the route has expired and is marked as an invalid route.

Note:	This control is valid only if you have selected Periodic update mode in the General tab.


Select the time before you remove a route from the routing table. This is the number of seconds between when a route expires and when it is removed from the routing table. The default value is 120 seconds. Valid settings are from 15 seconds to 259,200 seconds (72 hours).

Note:	This control is valid only if you have selected Periodic update mode in the General tab.


When this option is selected, routes learned on a network are suppressed in updates sent on that network. If this option is not selected, routes learned on a network are announced on the same network, as well. Split horizon is enabled by default.


With both split horizon and poison reverse enabled, routes learned on a network are announced with a metric of 16 (unreachable) in updates sent on that network.

Note:	Poison reverse is enabled by default. But enabling poison reverse is possible only after split horizon has been enabled.


When checked, new routes and metric changes trigger an immediate update, which includes only the changes. This is called a triggered update. The time between updates depends on the value of the Minimum seconds between triggered updates control, which you set in the General tab of the RIP for Internet Protocol Configuration dialog box.


When this option is selected, if RIP is being stopped on this interface, RIP sends its entire routing table out with all routes marked with a metric of 15. This enables other routers to immediately update their routing tables and mark that this interface is coming down instead of waiting to discover that the route is unusable.

If this option is selected, when the router is stopped, it advertises all of the routes that it makes available as being unreachable on all of its interfaces. This is enabled by default.


When this option is selected, a non-RIP route to a network(that is, an OSPF route or static route) in the routing table is discarded if a RIP route to that network is learned. By default, this option is disabled.


If this option is selected, host routes in received RIP announcements are accepted. By default, they are ignored.


If this option is selected, host routes are included in RIP announcements. By default, they are not included.


If this option is selected, default routes in received RIP announcements are accepted. By default, they are ignored.


If this option is selected, default routes (network ID 0.0.0.0) are included in RIP announcements. By default, they are not included.


Select this check box to enable IP on this interface and set the administrative status of the network to up.


Select this check box to enable router discovery advertisements over the interface. Clients use these messages to dynamically set their default gateways.

Windows NT implements router discovery by using multicast ICMP router advertisement messages. For more information on ICMP router discovery messages, see RFC 1256.


Type a value to increase the level of desirability in using this interface as the default gateway. A higher number means this gateway receives more traffic relative to other gateways on the same IP subnet.


Type the number of minutes a router discovery packet is advertised. The default is 10 minutes.


Type the number of minutes this advertisement is valid. The default is 30 minutes.


Applies packet filters to incoming packets on an interface. However, packet filtering must be enabled before packet filtering can take place.

To ensure packet filtering is enabled

1	Close this dialog box.

2	Under IP Routing, right-click Summary.

3	Click Configure IP parameters.

4	In the IP configuration dialog box, make sure Enable packet filtering is selected.


Applies packet filters to outgoing packets on an interface. However, packet filtering must be enabled before packet filtering can take place.

To ensure packet filtering is enabled

1	Close this dialog box.

2	Under IP Routing, right-click Summary.

3	Click Configure IP parameters.

4	In the IP configuration dialog box, make sure Enable packet filtering is selected.


Select this option to disable event logs in the Event Viewer administrative tool.


Select this option to log errors in the Event Viewer administrative tool.


Select this option to log errors and warnings in the Event Viewer administrative tool.


Select this option to log all information in the Event Viewer administrative tool.


Select this check box to enable IPX routing on this interface.


Select which control protocol to use when establishing the demand-dial connection.

These options are only visible for demand-dial interfaces. They cannot be configured for internal or dedicated interfaces.


Select this option if you are using PPP - that is, if your routers and clients use Windows NT.


Select this option if your routers and clients are using Novell.


Click to apply packet filters to packets coming in to the interface.


Click to apply packet filters to packets leaving the interface.


Select this check box if you want RIP to advertise routes on this interface.


Select this check box if you want RIP to accept advertisements that come from other routers over this interface.


Select this option to periodically advertise routes/services with the update and aging intervals.


Select this option to never update routes/services on this interface.


Select this option to enable this interface to perform updates only through static updates across demand-dial connections This is the default for demand-dial interfaces.


Type a number to specify how often routes/services are advertised on this interface. The default update interval is 60 seconds.


Type a number to specify how long routes/services are kept in the routing table. The number entered here - for example, 3 - is multiplied by the number in the update interval box - for example, 60 - to give you the total number of seconds that routes are kept in the routing table - 180 seconds.


Select this check box to deny the routes/services listed below.


Select this option to accept only the routes/services listed below.


Shows the list of routes/services to either deny or accept.


Click to add an address for filtering.


Select an address and then click to edit the filter.


Select an address and then click to delete it.


Indicates the interface for which you are setting the filter.


Type a 4-byte hexadecimal number (8 hexadecimal digits) that identifies the IPX network.


Type a 4-byte hexadecimal number (8 hexadecimal digits) that defines the range of network numbers you want to filter.


Select this check box if you want to advertise SAP services on this interface. By default, it is enabled.


Select this check box if you want to accept SAP service advertisements that come from other routers over this interface.


Select this check box if you want to respond to SAP GetNearestServer requests from IPX nodes on this interface. The SAP GetNearestServer request is sent out by IPX nodes attempting to locate the "nearest" server of a specific service type on the network. Nearest is defined as the SAP agent that is able to respond the quickest. For example, a NetWare client attempts to find the nearest NetWare server on the IPX internetwork for login purposes.

The router also replies to a get nearest service request from another router.


Type a hexadecimal SAP number. This is a 2-byte SAP Service Type expressed in hexadecimal (4 hex digits). A service type of "FFFF" can be used to indicate all service types.


Type the name of the service. This is the SAP Server Name, which can be up to 48 bytes long. A service name of "*" can be used to indicate all service names.

Note:	The "*" wildcard cannot be used within a service name.


Type a 4-byte IPX Network Number in hexadecimal (8 hex digits) for a network you can reach through this interface.


Type the 6-byte MAC address in hexadecimal (12 hex digits) of the next-hop router to be used to reach the network defined above.


Type the number of ticks (1/18 second) it takes a packet to reach the network.


Type the number of hops, that is, the number of routers to be crossed to reach the network.


Type the name of the service that can be reached through this interface.

The SAP Service Name can be up to 48 bytes long. Names under 48 bytes will be terminated with an ASCII NULL in the Server Name field in the SAP header.


Type the 4-byte IPX Network Number in hexadecimal (8 hex digits).


Type the 6-byte IPX Node Address in hexadecimal (12 hex digits).


Type the 2-byte IPX Socket Number in hexadecimal (4 hex digits).


Type the first 15 characters of the name of the computer or the name of the service that is advertised by NetBIOS. For example, when you use a net use command this is the name of your computer.


Type the last byte of the name. This is the last byte of the full 16-character NetBIOS name expressed in hexadecimal (2 hex digits), which is used to indicate the type of NetBIOS process.

If you are not sure what this is, leave this option blank.


Select this check box to accept NetBIOS broadcasts on this interface. By default, this setting is enabled for LAN interfaces and disabled for demand-dial interfaces.


Select this check box to always deliver all NetBIOS over IPX broadcasts to all interfaces except the interface on which the NetBIOS over IPX broadcast was received (except if the NetBIOS over IPX broadcast has already been on the IPX network to which the outgoing interface is attached).

This is the default setting for LAN interfaces. If enabled for a demand-dial interface, the demand-dial connection will be established whenever a Windows NT-based router receives a NetBIOS over IPX broadcast.


If this option is selected, NetBIOS broadcasts are never delivered on this interface. (Windows NT-based routers silently discard them.)

This is the default setting for demand-dial interfaces.


If this option is selected,only broadcast packets that are defined for the statically configured names are delivered.

These names are configured in the Static NetBIOS Name dialog box.


This setting can be used for demand-dial interfaces.

If this option is selected, packets are broadcast if an interface is up. If the interface is not up, the router waits to broadcast the packet; that is the router does not bring up the interface specifically to broadcast the packet.


Type the destination, host, subnet address, network address, or default gateway. The destination for a default route is 0.0.0.0.


Type the network mask for the static route.

The Netmask number is used in conjunction with the Destination number to determine when the route will be used. For example, a host route has a mask of 255.255.255.255, a default route has a mask of 0.0.0.0, and a subnet or network route has a mask somewhere in between these two extremes. The mask of 255.255.255.255 means that only an exact match of the Destination number can use this route. The mask of 0.0.0.0 means that any Destination can use this route. Route table entries are ordered from the most restrictive mask to the least restrictive mask.


Type the IP address of the next router where this packet needs to be sent.

The gateway must be directly reachable by this router. This means the two routers must share a common LAN or WAN link.

Note:	The gateway address on a point-to-point link (such as a modem or ISDN connection) is configured but not used. The interface is what is important on a point-to-point link.


Select the number of router hops to the destination or the cost of the route.

This is used by the router to choose the best route.


Select the LAN or demand-dial interface to be used to reach the next router.


This dialog box appears only when you have more than one IP address configured on the interface. All OSPF settings on the General, Neighbors, and Advanced tabs pertain to the IP address that you have selected. This means that on each tab, you must select an IP address in the IP Address box and then configure the OSPF settings, select another IP address and configure settings, until you have configured settings for all IP addresses.


Select this check box to enable OSPF on the interface.


Select the area for the interface. An interface can belong in only one area.

If you have multiple IP addresses, you can select a different area for each IP address.

To add a new OSPF area, see To create an OSPF Area.


Assigns the level of priority for this interface. Larger numbers indicate higher priority. When two routers attached to a network both attempt to become designated router, the router with the highest router priority setting takes precedence. If there is still a tie, the router with the highest router ID value takes precedence.

However, when you set up a new router interface, if a designated router exists, the new router defers to the existing designated router, regardless of the priority value you configure for the new interface.

Note:	If the interface has a priority value of 0, it cannot become the designated router.

The priority setting is ignored for point-to-point links.


Select the cost of sending a packet out of this interface. Cost indicates ranking and is determined by the administrator of the network. The term metric is often used synonymously with cost. The value set here is advertised as the link cost for this interface in the router's link state advertisement.

The lower the cost, the more often the interface is used. Faster interfaces usually have lower costs. For a broadcast interface, the default setting is 1; for a point-to-point interface, the default is 4. The maximum setting is 32,767.


If you have enabled passwords for the area, type the password used for this interface, using any combination of uppercase or lowercase letters or numbers.

All interfaces in the same area that are on the same network must use identical passwords.

Interfaces in the same area that are in different networks can have different passwords.

By default, passwords are enabled and the password is "12345678."

Passwords are transmitted in clear text so this feature is for identification, not security.

If this option is unavailable, you must enable passwords for the area. For more information, see To configure an OSPF Area.


Click to specify a broadcast OSPF interface. OSPF then works as a multiple access broadcast network; that is, multiple routers can be connected to the network. Broadcast networks can address a single physical message to all the attached routers. Broadcast network types are Ethernet, Token Ring, and FDDI.


Click to specify a point-to-point OSPF interface. A point-to-point configuration is a connection between a single pair of routers. Examples of point-to-point network types are T1, T3, and dial-up links.


Click to specify a nonbroadcast multiple access (NBMA) OSPF interface. Examples of NBMA network types are X.25, Frame Relay, and ATM (asynchronous transfer mode).

Note:	If you specify this type of connection, you can set neighbors by using the Neighbors tab.


 The Neighbors tab is used exclusively to configure the IP addresses of neighboring routers in an NBMA network (such as an X.25 or Frame Relay configuration).

Displays the list of neighbors and the priority associated with them.

Use the Add button to list all other routers attached to the nonbroadcast network. Each router is listed by its IP interface address on the network. Also, for each router listed, that router's eligibility to become designated router must be defined. When an interface to a nonbroadcast network comes up, the router sends Hello packets only to those neighbors eligible to become designated router until the identity of the designated router is discovered.


Adds a neighbor address and its priority to the NBMA neighbors list .

Type the address in Neighbor Address, select a priority in Priority, and then click Add.


Removes a neighbor address and its priority from the NBMA neighbors list.

In the NBMA neighbors list, select the address that you want to remove, and then click Remove.


Type the IP address of the neighbor that you want to add. The IP address to add is the IP interface address by which the neighbor is listed on the network.

Note:	This is not the router ID of the neighbor.


Select the router priority of the neighbor.

Also, for each router listed, that router's eligibility to become designated router must be defined. When an interface to a nonbroadcast network comes up, the router sends Hello packets only to those neighbors eligible to become designated router until the identity of the designated router is discovered.


Select the estimated number of seconds it takes to transmit a link state update packet over this interface. This value should take into account the transmission and propagation delays of the interface. The default setting is 1 second.


Select the number of seconds between link state advertisement retransmissions for adjacencies belonging to this interface. This value should exceed the expected round-trip delay between any two routers on the attached network. However, if this value is not conservative, needless retransmissions result. The value needs to be larger on low-speed serial lines and virtual links. A sample value for a local area network is 5 seconds.


Select the interval in seconds between transmissions of hello packets by the router on the interface. This setting must be the same for all routers attached to a common network. The shorter the hello interval, the faster topological changes are detected. However, a shorter interval also results in more OSPF traffic.

A sample value for an X.25 network is 30 seconds. A sample value for a local area network is 10 seconds.


Select the number of seconds before a silent remote router is declared down. A silent router is determined to be down if your router does not receive a response to hello packets sent to the remote router within the specified interval. For example, if your hello interval setting is 15 seconds and your dead interval is 60 seconds, after sending four hello packets and receiving no acknowledgment or response, your local router declares that the remote router is down.

Note:	This setting should be a multiple of the hello interval (commonly 4). This value must be the same for all routers attached to a common network.


If a neighboring router is down (hello packets have not been sent for the number of seconds determined by the dead interval setting), it might still be necessary to send hello packets to the dead neighbor in order to determine if the connection has been restored. This is called the poll interval.

Select the number of seconds between OSPF network polls for NBMA interfaces only.

Set the poll interval to be at least twice as long as the dead interval. A sample value for an X.25 network is 2 minutes.


Select the maximum size of IP packets carrying OSPF information.

The maximum transmission units (MTU) size relates to the speed and expected error rate at which a network sends and receives data. For example, on a slow, error-prone network, you reduce the size of packets. On a fast, reliable network, you increase the packet size.

The default value of 1500 is the default IP MTU for 10-MB Ethernet. The maximum packet size on a 100-MB FDDI ring is 4096 bytes. The size can be much smaller on a radio channel.


These credentials are used when dialing out over a demand-dial connection.

Type the user name to use when dialing in to a remote router. This user name must match the name of a user account on the remote router that has been granted dial-in permissions. This user name must also match the name of an interface on the remote router.

For example, if the remote router has an interface with the name "NY to Seattle connection," then the remote router must also have created a user in User Manager for Domains with the name "NY to Seattle connection" with dial-in permissions. Therefore, the user name to enter here is "NY to Seattle connection."


If the user account that has been created on the remote router is in a different domain, type the name of the domain. Otherwise, Windows NT assumes that the user account is in the default domain for this computer.


Type the password to use when dialing in to the remote router. This is the password for the user account created on the remote router.


Type the password again to confirm that you typed the password correctly.


Displays a list of column heading options for interfaces in Routing and RAS Admin. The Interface, Type, IP Address, Administrative status, Operational status, Incoming bytes, Outgoing bytes, and Filters check boxes are selected by default. You can view additional information about an interface by selecting the appropriate check box, which adds the corresponding column heading. To omit column headings from the interface list, clear the appropriate check boxes.


Click to move the selected column heading option up in the list order.


Click to move the selected column heading option down in the list order.


Adjusts the column width of the selected column. Move the slider to the right to make the column heading narrower; move it to the left to increase column width.


Select this option to accept all packets that do not match the filters in the list box.

All incoming packets are compared to the filters shown in the list box below. If a packet matches a filter, the packet is dropped. If the packet does not match a filter, the packet is accepted.

This option applies to all the filters that you have added. You cannot change this option for individual filters.


Select this option to accept all packets that match the filters in the list box.

All incoming packets are compared to the filters shown in the list box below. If a packet matches a filter, the packet is accepted. If the packet does not match a filter, the packet is dropped.

This option applies to all the filters that you have added. You cannot change this option for individual filters.


Displays a list of all configured filters.


Click to add a filter.

You can set filters based on where the packet is coming from (the source), where the packet is going (the destination), or what protocol the packet is using. You can set all three of these values for a filter or set any one or combination of the three, depending on the level of control that you want.


Select a filter and then click to edit the filter properties.


Select a filter and then click to remove it from the filter list.


Select this check box to have the filter check the network from which the packet is coming. After selecting this, you must specify a network address and subnet mask.


Type the address of the network from which the packet was sent. You must also specify a subnet mask.


Type the subnet mask that corresponds to the network address in the IP Address box.


Select this check box to have the filter check the network to which the packet is going. After selecting this, you must specify a network address and subnet mask.


Type the address of the network to which the packet is going. You must also specify a subnet mask.


Type the subnet mask that corresponds to the network address in the IP Address box.


To set a filter based on the protocol type of the packet, select a protocol from this box. The default is Any protocol. If you select Other, you must enter a protocol identifier in the Protocol box.


Type the port number specified by the source to be used by the filter.

Some applications use well-known ports to send and receive packets. You can set a filter for one of these ports if you know what numbers the application uses for the protocol specified in the Protocol box. For example, you can try to block FTP traffic or allow only PPTP traffic. PPTP uses TCP source port 1723 and IP protocol ID 47. For more information on how to set up a PPTP filter, see Setting PPTP Filters.


Type the port number used by the destination for the packet.


Select this option to accept all packets that do not match the filters in the list box.

All incoming packets are compared to the filters shown in the list box below. If a packet matches a filter, the packet is dropped. If the packet does not match a filter, the packet is accepted.

This option applies to all the filters that you have added. You cannot change this option for individual filters.


Select this option to accept all packets that match the filters in the list box.

All incoming packets are compared to the filters shown in the list box below. If a packet matches a filter, the packet is accepted. If the packet does not match a filter, the packet is dropped.

This option applies to all the filters that you have added. You cannot change this option for individual filters.


Displays a list of all configured filters.


Click to add a filter.

You can set filters based on where the packet is coming from (the source),  where the packet is going (the destination), or the type of packet to use. You can set all three of these parameters for a filter or any one or combination of the three, depending on the level of control that you want.


Select a filter and then click to edit the filter properties.


Select a filter and then click to remove it from the filter list.


Type the 4-byte network number used to uniquely identify the network from which the packet was sent. You must also specify a subnet mask.


Type the subnet mask that corresponds to the network address in the IP Address box.


Type the 6-byte node address used to store the IEEE-administered physical or hardware address assigned to the network interface card of the node.

The source node is an optional filter value.


Type the 2-byte socket number that identifies the individual software or client process that is communicating. The use of socket numbers allows the sending and receiving of packets to the proper process.


Type the 4-byte network number used to uniquely identify the network to which the packet is going. You must also specify a subnet mask.


Type the subnet mask that corresponds to the network address in the IP Address box.


Type the 6-byte node address used to store the IEEE-administered physical or hardware address assigned to the network interface card of the node.

The source node is an optional filter value.


Type the 2-byte socket number that identifies the individual software or client process that is communicating. The use of socket numbers allows the proper sending and receiving of packets to the proper process.


Type the packet number specified by the source to be used by the filter.

This should be a 4-digit hexadecimal number from 0000 to FFFF.


If you are connecting to a router:

Type the name of the router to which you want to connect. For example:  \\routername.

If you are connecting to a domain:

Type the name of the domain you want to view. For example: domainname (without the \\).


Type the number of seconds to display updated information in Routing and RAS Admin. Before the interface will refresh, you must also select the Auto Refresh option in the Options menu.


A list of all the entries in the current phonebook. Select an entry and then click Dial. You can also edit, clone, or delete entries by clicking More.

The default phonebook is the system phonebook (rasphone.pbk). To select a different default phonebook, click More and choose User preferences. In the Phonebook tab select a personal or alternate phonebook.


Click to add an entry to the phonebook.


Click to see more commands such as edit, delete, or clone an entry.


Displays the complete number that will be dialed, including prefixes, suffixes and telephony dialing properties. Click Location to change how the number appears or type a new number in the box to temporarily override the number associated with the entry.


Specifies the location from which you are dialing.

If you have a laptop computer, it might be useful to set location properties for your various locations, such as your office, home, or hotel. Thus, depending on your location setting, your phonebook entries can be customized to use specific area codes or calling card numbers.


Click to change the properties of the selected location or create a new location.

The dialog box that appears depends on whether or not you selected the Use Telephony dialing properties check box in the Basic tab. By default, this check box is not selected and the prefix and suffix controls from previous versions of RAS are available.

Select the check box if you want to use the telephony dialing features. The circumstances when you might want to use these features are when you are calling long distance or using a credit card.


Click to dial the phonebook entry selected in the Phonebook entry to dial box.


Click to close the dialog box


Type the name of the entry you want to dial (company name or server name). Choose any name you like, from 1 to 256 characters. Typically, the name of the remote server or the type of connection is a good choice, for instance, "PPP Internet connection" or "SLIP Internet connection".

This name appears in the phonebook list.


An optional box for you to store notes on the entry.


Choose the country of the dial-up server you are calling.


Type the area code of the dial-up server you are calling.

If the dial-up sever is in a country other than the United States, type the city code here, but do not include the leading 0. For example, if the city code is 071, just type 71.


Type the phone number of the dial-up server. See Phone Number Modifiers for special command sequences.


Click to add secondary phone numbers to the entry. If the first phone number cannot be reached, the secondary phone numbers are dialed until a successful connection is made.


Select the preferred device to dial. If the first device fails, any other devices of the same type will be used to try to make a connection if you select the Use another port if unavailable check box.

In the Dial using box you can also select multiple lines to be used when you are dialing. This uses Multilink functionality which combines multiple physical links into a logical "bundle" to create an aggregate link that increases your bandwidth.

To use Multilink, both the clients and servers must have Multilink enabled.

Click Configure to choose which modems or adapters to use for the connection.


Click to configure device-specific settings. For example, if you are using modems to make a connection, click to set the speed of your modem and enable modem compression.


Select this check box to use the telephony dialing features. These are useful when you are calling long distance or using a credit card. Selecting this check box brings up the telephony dialing page when you click Location in the Dial-Up Networking dialog box. If you do not select this check box, the prefix and suffix controls from previous versions of RAS appear when you click Location.

Do not select this check box if you are dialing a number within your internal corporation.


Choose the dial-up sever type. If you are not sure, choose PPP. If you are calling a SLIP server, choose SLIP. If you are dialing a server that uses an older RAS protocol, you should choose Windows NT 3.1, Windows for Workgroups 3.11.

Some of the protocols and other options in the Server tab may not be available depending on your selection.


Network protocols are the protocols you use to communicate with servers on the LAN once you are connected to a dial-up server. See your network administrator if you do not know which protocol to select.

You can select more than one protocol. Protocols already installed on the computer will be checked by default.


The Transmission Control Protocol/Internet Protocol (TCP/IP) is a networking protocol that provides communication across interconnected networks.

TCP/IP is the suite of network protocols used on the Internet.


The NetWare suite of protocols used in a Novell network.


NetBEUI is network protocol native to Microsoft Networking. This protocol is the Microsoft implementation of the NetBIOS standard.


Click to set TCP/IP settings for the phonebook entry. If you are calling a Microsoft server (Windows NT, Windows 95, Windows for Workgroups, or other Microsoft RAS server) you do not need to configure TCP/IP settings.


Dial-Up Networking offers software data compression in addition to supporting modem compression. So, you do not have to turn on modem compression to benefit from a faster throughput.

Select this check box to enable software compression.

For recommendations about getting the most out of compression, see Compression Recommendations.


Select this check box to enable newer PPP features. These extensions may cause problems when calling servers with older PPP software. Clear the check box only if consistent problems occur.

Clearing this check box prevents LCP from sending Time-Remaining and Identification packets and requesting callback during the LCP negotiation of PPP.


Select this check box if you do not want to use a script or terminal after dialing.


Select this check box to use a terminal box after dialing.

See Using RAS Terminal for Remote Logons


Select this check box to use a script after dialing.


Select which script to use after dialing. These scripts are part of Switch.inf, in which you can modify or create new scripts.

See Automating Remote Logons Using SWITCH.INF Scripts


Click to instantly access  Switch.inf in order to modify or create new scripts.


Click to update the script list box after editing Switch.inf.


Click to use a script before dialing, for instance, when using an intermediary device on the client side.


You can choose the rules used to negotiate authentication and encryption with the dial-up server. Authentication deals with verifying clients to servers and setting encryption prevents someone from monitoring data on the communication line.


Permits connection using any authentication requested by the server (MS-CHAP, MD5-CHAP, SPAP, PAP). This setting is the most permissive and can be used when you are not worried about passwords. This option is useful if you are calling a non-Microsoft server.


Permits connection using any authentication requested by the server except PAP.

This option is useful if you are calling a non-Microsoft server and do not want to transmit clear text passwords on the communication line.


Permits connection using MS-CHAP authentication only.

This option is useful if you are calling a Microsoft server. You can also choose to use data encryption or change password support over Dial-Up Networking.


All data sent over the wire is encrypted. This option is available only on Windows NT version 3.5 or later RAS computers. Windows NT RAS provides data encryption using the RSA Data Security Incorporated RC4 algorithm.

If you select this check box, the connection will hang up if it does not encrypt.


This option is an optimization appropriate for those using a home computer as an alternate workstation on an office network. Selecting this option causes the credentials entered at CTRL+ALT+DEL logon to be used for the RAS connection. This setting eliminates the need to logoff/logon when you are attempting a RAS connection after the account password has been changed on the office workstation.


If you have previously chosen to save your password in the dialog box that prompts you for your username, password and domain when dialing an entry, you can click to erase that password.


Select this check box to authenticate the remote router when you try to make a connection. This means that when making a connection, in addition to the remote router checking your credentials, for added security, you also authenticate the remote router.

To authenticate the remote router, you must create a user account in User Manager for Domains with dial-in privileges for the remote router.


Select this check box to use the strongest encryption algorithm that you have installed on your computer. For example, if 128-bit encryption is installed on your computer, checking this box forces all connections to use 128-bit encryption.

Note:	If you select Require strong data encryption then you can only connect to Windows NT routers that have enabled Require strong data encryption for incoming calls.


Choose the name of the X.25 network you are calling.


Enter the X.25 address (the X.25 equivalent of a phone number) for the dial-up server you want to call.


Filling in these boxes is optional, in most cases you do not need to type anything further.


Enter additional connection information required by the X.25 host computer. Typically, you should leave this field blank unless your system administrator advises otherwise.


Enter any additional facility parameters you want to request from your X.25 provider. For example, some providers support /R to specify reverse charging. For details, consult your X.25 documentation or provider.


Select this check box to view and edit the phone` number you are dialing in the Dial-Up Networking dialog box.

Clear the check box to prevent the phone number from being displayed in the dialing status popup during the connection sequence.


Select this check box to view and edit the location setting in the Dial-Up Networking dialog box.


Select this check box to start Dial-Up Networking Monitor before dialing a number.


Select this check box to see the connection status during a call.

Clear the check box if you prefer connections to silently connect and show status only when success or failure has been determined This is most useful with Autodial.


Select this check box to close Dial-Up Networking after a successful connection.


Select this check box to enable you to edit the Dial-Up Networking phonebook when you are logging in to Windows NT and have selected the Logon using Dial-Up Networking check box.


 Select this check box to enable a user to create new TAPI dialing locations when a user is logging in to Windows NT and has selected the Logon using Dial-Up Networking check box.

Clear this check box to prevent a user that is logging in from changing the dialing locations or creating a new location.


Select this check box to use the Dial-Up Networking wizard to create new phonebook entries.


Select this check box to receive a prompt before a connection is automatically established. This feature is useful for tracking every autodial connection and being aware, for instance, that an expensive ISDN line is being used.

The Remote Access Autodial service must be running in order for this option to take effect.


Select each location where you want to enable RAS Autodial.

RAS Autodial maps and maintains network addresses to phonebook entries, allowing them to be automatically dialed when referenced-whether from an application or from the command line. A network address can be an Internet host name, an IP address, or a NetBIOS server name.

The Remote Access Autodial service must be running in order for this option to take effect.

See RAS Automatic Dialing


Specify the number of times to automatically redial the number. No redial means zero.


Specify the number of seconds to wait before automatically redialing. This gives the remote device time to reset.


Specify the amount of idle seconds before a connection hangs up.

Keep in mind that the dial-up server also has a disconnect timer. If this control is set to a high timeout number, there is no guarantee that the connection will not disconnect before the time passes. This is because the server may choose to disconnect you before the time set here.

The Remote Access Autodial service must be running in order for this option to take effect.


Select this option if you do not want the dial-up server to call you back.

This option is for the convenience of a remote user who calls from various places. It is not a security feature. Select Set By Caller for clients that call from various locations and different phone numbers. When the user's call reaches the remote access  server, the following steps occur:

1	The server first determines if the user name and password are correct.

2	If they are, the Callback dialog box appears on the user's computer.

3	The user types the current callback number in the dialog box and waits for the server to return the call.

Set this option to minimize telephone charges for anyone calling in from various locations, such as field representatives.


Select this option if you want the dial-up server to ask whether or not you want to be called back during the connection process.


Select this option if you want the dial-up server to call you back. You must then supply phone numbers for each device.


Select the device to be used during callback and click Edit to enter a phone number.


Click to enter a phone number for the dial-up server to use when calling you back.


Click to delete the selected device from the callback list.


Enter the number for the dial-up server to use when calling you back.


Use the following options to select the default phonebook for use in the Dial-Up Networking dialog box.


Select this option to use the system phonebook. This is the default phonebook (rasphone.pbk in the \SYSTEM32 folder)


Select this option to use a personal phonebook. A personal phonebook is created with protection mode so that another user who logs on to the same computer will not be able to see your phonebook. Password protection mode only works on NTFS file partitions.


Select this option to use a phonebook that is located outside the \SYSTEM32 folder. For example, a phonebook on another computer.


Select a phonebook from the list or type the complete path to the phonebook.

Click Browse to search for a phonebook.


Click to find other phonebooks on your computer or to see a list of phonebooks on other computers.


Select the type of ISDN connection. The choices are in order from the highest quality (64K Digital) to the lowest (56K Voice).


Select this check box to start at the selected line type and negotiate to a lower quality line type, depending on the line's condition.

Note:	Some ISDN cards negotiate both the line type and the number of channels if the Negotiate line type check box is selected. In other words, not only will the card start negotiating at highest quality line type (64K digital) and fall back to lowest quality (56K voice), but in many cases it will also fall back from multiple channels to fewer channels if necessary.


Select this check box if the server you are dialing into supports only proprietary protocols. For instance, using DigiBoard devices on both the server and the client.

Clear this check box to use Multilink over multiple ISDN lines. Multilink does not require proprietary protocols on the server or client.


Select this check box to compress data before transmitting it. If you enable hardware compression, turn off software compression.

Note:	Not all ISDN cards offer hardware compression. If this feature is turned on and your card does not offer compression, your data throughput will not improve. If you do not know whether your card has compression, check with the card's manufacturer.


If your card allows you to aggregate more than one ISDN channel, and the remote access server's ISDN card is configured to allow channel aggregation, you can select more than 1 channel to improve throughput. See the section "ISDN Phone Numbers" in Adding/Editing/Cloning an Entry.

Not all ISDN drivers let you restrict channel aggregation. If you have a non-restricting driver and your computer is configured to receive calls, ask clients dialing in to specify only one or two channels. Otherwise, one user with several ISDN cards could monopolize all channels on the server.

Note:	You cannot connect through more channels than the number available on your ISDN card(s). In fact, selecting more than the maximum available may prevent you from connecting.


Displays the installed modem.

Note:	To change your modem or install a new modem, choose the Network icon in Control Panel. In the Services tab, select Remote Access Service and then click Properties. See the online Help in the dialog boxes for more information.


Select the speed at which your modem begins to negotiate with the remote access server's modem. The speed, in bits per second (bps), may increase or decrease during negotiation.


Selecting a hardware feature that is not supported by your modem has no effect on performance.


Select this check box to enable hardware handshaking. This feature enables the modem to tell remote access software when the line is congested or clear, so that the remote access software can temporarily stop transmitting data when necessary. This handshaking streamlines data transmission, prevents overrun errors, and thus improves overall data throughput.


Select this check box to check errors on blocks of data through cyclic redundancy checks (CRCs). Modem error control causes the modem to retransmit garbled data, ensuring that only error-free data passes through the modem. For more information, see MNP4 and V.42.


Select this check box to compress the modem-to-modem data stream, reducing the number of bytes transmitted and therefore reducing the transmission time. The reduction achieved depends on the amount of redundancy in the transmitted data.

Note:	Software compression is more effective than hardware compression because a much larger pattern buffer is available on the computer than on the modem. In addition, modem compression delays the first transmission while the modem's pattern buffer is filled at computer-to-modem speed. Software compression accomplishes this task at the much faster memory speed and transmits compressed data over the entire computer-to-computer link rather than just the modem-to-modem segment.

In general, you should not enable modem compression and software compression at the same time, because no benefit is gained from compressing pre-compressed data. In fact, it may actually increase the size of the transmitted data, depending on the algorithm used by the modem.


Select this check box to enter AT commands to the modem manually when dialing rather than executing the scripted commands. Enable this feature when testing modem strings for new entries in the modem script file (MODEM.INF) and for unusual situations where interaction is required midway in the dial sequence.

In general, do not enable this feature when dialing with the telephone keypad, for example, when connecting through a switch controlled by a human operator.


Select this check box if you do not want to hear the modem dial tone and connection sounds.


Your Windows NT domain password has expired. Please change your password now by filling in the fields in this dialog box.

Passwords are case-sensitive. Remember your use of uppercase and lowercase letters when you type a new password.


Type the current password.


Type the new password.


Type the new password again to confirm it.


The dial-up server is configured to call you back at a number you specify for convenience purposes, such as reversing the calling charges.

You can automatically answer this dialog box by choosing the User preferences command from the More button and then selecting options in the Callback tab.


Type the number at which you want the remote access server to call you back.


Your modem (or other connecting device) has reported an error. If you are using a supported modem, turn the modem off and then back on. Close and restart the Remote Access Service, and then redial.

If your modem is not supported by Remote Access, contact your modem's manufacturer. For a list of supported modems, see the Windows NT Hardware Compatibility List.

Make sure you have correctly configured your modem for Remote Access. To check your configuration, see Reconfiguring Dial-Up Networking.


Counts down the number of seconds until redialing based on settings in the Dialing tab in the User preferences dialog box.


At least one of the protocols selected for the entry failed to connected.

Click Accept to connect using the protocols shown.

Select the check box to use only the protocols that connected the next time you dial. Or, to change the connection protocols for an entry, in Dial-Up Networking, select an entry and click More. Select Edit entry and modem properties. In the Server tab, select the network protocols you want to use for the connection.


Click to connect using the protocols shown.


Click to hang up the connection.


Select this check box to use only the protocols that connected the next time you dial.

To change the connection protocols for an entry, in Dial-Up Networking, select an entry and click More. Select Edit entry and modem properties. In the Server tab, select the network protocols you want to use for the connection.


Dial-Up Networking Authentication credentials are typically the same as your network logon credentials. Dial-Up Networking uses these credentials to verify that you have the right to physically access the network. Dial-Up Networking does not actually log you on, so after your connection is established you may need to log on (by pressing CTRL+ALT+DEL for Windows NT) to access protected network resources.


Type your remote access user name.


Type your remote access password.


If you are calling a non-Microsoft server, you do not have to enter a domain.

If you are calling a Microsoft server, the domain name you enter should be the Windows NT domain that the Windows NT RAS server or your Dial-Up Networking account is in. This is not the DNS domain name given by some PPP/SLIP providers. For example, you would enter accounting, not www.halcyon.com. For information about domains and trust relationships, see the Windows NT Server Concepts and Planning Guide.

If you are connecting to MSN, type MSN\username in the Username box and leave the domain name blank. Your username, including MSN\, cannot exceed 20 characters.


Select this check box to save your password for the entry. The next time you make a connection with this phonebook entry, this authentication dialog box will not appear.

If select this check box and later want to change the password for the entry, you must edit the phonebook entry and in the Security tab, click Unsave password.


Dial-Up Networking clients must have an IP address. Select this option for an address to be assigned automatically by the dial-up server.


Select this option if you require a specific IP address as a Dial-Up Networking client and enter the required IP address.


Enter the required IP address. The dial-up server must be configured to permit clients that use a specific IP address.


Dial-Up Networking clients may require a server that maps the IP addresses used by computers to the friendly names used by people. For example, 198.105.232.1 is an IP address that users refer to as ftp.microsoft.com.

Domain Name Service (DNS) servers are used on TCP/IP networks worldwide. Windows Internet Name Service (WINS) servers have been introduced in Windows NT version 3.5 and later. Both can provide name resolution to Windows NT Dial-Up Networking clients.

Select this option to allow the dial-up server to assign DNS or WINS servers to Dial-Up Networking clients.


Select this option to specify the DNS and WINS servers (and alternate or backup servers).

Any address set to 0.0.0.0 or left blank does not change the configuration for that particular name server address, as if the server had rejected the option.


Enter an IP address to use a specific DNS server.


Enter an IP address for an alternate DNS server.


Enter an IP address to use a specific WINS server.


Enter an IP address for an alternate WINS server.


This check box sets Van Jacobson IP header compression during log on and negotiation with a PPP server.

When checked (the default) Dial-Up Networking will attempt to use VJ compression. This may or may not be successful depending on the capabilities of the remote PPP server, however, failure to negotiate VJ compression does not prevent the connection from working.

When cleared, Dial-Up Networking will not request or accept VJ compression. Some older versions of non-Microsoft PPP server software do not work with Windows NT Dial-Up Networking when VJ header compression is enabled. You should clear this box only when you successfully connect but you cannot transfer IP data in one or both directions.

If cleared, this check box overrides the registry values:

\\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rasman\PPP\IPCP\AcceptVJCompression and RequestVJCompression.


This check box applies only to Dial-Up Networking clients that are simultaneously connected to a LAN and using a network card. When checked, packets that cannot be routed on the local network are forwarded to the default gateway on the remote network. In addition, address conflicts between the remote and local networks will be resolved in favor of the remote network.


Select this option if you do not want to register the interface to any WINS or DNS servers when connecting to a remote router. This is the default option when routers connect to other routers.

If your router registers WAN interfaces with a WINS or DNS server and the interface goes down, then attempts to ping your router by name might result in a machine unreachable message. Selecting this option means that if a WAN interface goes down, the name server will not return an invalid IP address for your router because the WAN interface was not registered with the name server.

The only reason to change this option to specify name server addresses or request name server addresses from the remote router is if your router has only WAN interfaces and you want your router to be reached by name. For this case you must register at least one WAN interface with the name server.


Dial-Up Networking clients can connect to a SLIP server and must supply an IP address. You can pre-enter the IP address here that you would normally enter in the Terminal window. Only enter an address here if the IP address the server assigns you at connection time is the same every time you connect.


Specifies the DNS and WINS servers (and alternate or backup servers).

Any address set to 0.0.0.0 or left blank does not change the configuration for that particular name server address, as if the server had rejected the option.


Enter an IP address to use a specific DNS server.


Enter an IP address for an alternate DNS server.


Enter an IP address to use a specific WINS server.


Enter an IP address for an alternate WINS server.


Dial-Up Networking SLIP supports Van Jacobson (VJ) TCP/IP packet header compression. VJ is a protocol optimization widely supported in SLIP implementations. Some SLIP implementations do not support VJ.

When this check box is cleared (the default) Dial-Up Networking SLIP attempts to detect compressed packets and, if found, automatically shifts into VJ mode. This gives the best chance of a successful connection and, in most cases, the best performance available.

In some cases where both ends are attempting to detect compression, compression may not be activated. If you are certain that the remote server supports VJ compression, select this check box to activate compression and improve performance. You can verify that compression is occurring by monitoring the compression information in the Dial-Up Networking Monitor Status tab.

Note:	If this check box is selected and the remote server does not support VJ compression, inbound traffic will continue normally but outbound traffic will not succeed. In this case, since most applications require communication in both directions the session will usually appear stopped.


This check box applies only to Dial-Up Networking clients that are simultaneously connected to a LAN and using a network card. When checked, packets that cannot be routed on the local network are forwarded to the default gateway on the remote network. In addition, address conflicts between the remote and local networks will be resolved in favor of the remote network.


Choose an outgoing frame size. The default setting is 1006; 1500 is also available if your remote access server accepts 1500-byte packets.


RAS Terminal is a character-based window that displays the logon sequence from the remote computer. Typically, you can use this window to interact with the remote computer for logging on. Alternatively, you can automate this manual logon using scripts. See Using RAS Terminal for Remote Logons for more information.

To change your before and after dialing options, use the Script tab in Dial-Up Networking.


Enter an IP address for the remote computer.


Click after you have completed all interactions with the remote computer.


Dial-Up Networking Multilink combines multiple physical links into a logical "bundle." This aggregate link increases your bandwidth. The most common use is bundling ISDN channels, but you can also bundle two or more modems or a modem and an ISDN line. To use Multilink, the dial-up server must have Multilink enabled.

Select the devices you want to link together during a call.


Click to add new or alternate phone numbers for the device.


Click to configure device-specific settings. For example, if you are using modems to make a connection, click to set the speed of your modem and enable modem compression.


Choose a device on your computer to view its connection status.


When a connection is active, this shows the current use of the device - for clients it shows the phonebook entry, for servers, it shows the user connected to the phonebook entry.

If the condition is inactive then there are no current connections based on the entry.


The speed in bits per second (bps) at which data is being transferred between modems.


The number of seconds since a physical connection was established.


Displays the status for incoming data.


Displays the status for outgoing data.


Displays the errors you might have during a connection.


The total number of bytes received over this connection. This number represents the bytes after they have been decompressed.


The number of logical network frames received from the server. The format of the frame depends on the network protocol in use. The maximum size of a frame is 1514 bytes. Well-written client/server applications transmit a small number of full or almost full frames. If you observe large numbers of small frames, the application you are running was probably not designed to run efficiently across slow links.


The ratio of compression achieved on received data, where higher is better. For example, if 400 incoming bytes decompress into 1,000 bytes, the compression ratio is 60 percent. This value refers to software compression only. The compression ratio depends on the amount of redundancy in the data received. For example, text and bitmaps compress well, but executable files and previously compressed data do not.

Connections using IP protocol VJ header compression (if active) is figured into this number. This entry may be non-zero even when Disable Software Compression (which applies only to data, not headers) is selected.

Note:	Software compression is not attempted on some frames, for example, multicast datagrams or very small frames. Such frames are not included in the compression computation.


The total number of bytes sent over this connection. This number represents the bytes before they have been compressed.


The number of logical network frames sent to the server. The format of the frame depends on the network protocol in use. The maximum size of a frame is 1514 bytes. Well-written client/server applications transmit a small number of full or almost full frames. If you observe large numbers of small frames, the application you are running was probably not designed to run efficiently across slow links.


The ratio of compression achieved on transmitted data, where higher is better. For example, if 1,000 bytes are compressed into 400 bytes before transmission, the compression ratio is 60 percent. This value refers to software compression only. The compression ratio depends on the amount of redundancy in the data being transmitted. For example, text and bitmaps compress well, but executable files and previously compressed data do not.

Connections using IP protocol VJ header compression (if active) is figured into this number. This entry may be non-zero even when Disable Software Compression (which applies only to data, not headers) is selected.

Note:	Software compression is not attempted on some frames, for example, multicast datagrams or very small frames. Such frames are not included in the compression computation.


Errors caused by the failure of a cyclic redundancy check (CRC). A CRC error indicates that one or more characters in the data packet arrived garbled from the server.


An expected character was not received in time. When this happens, the software assumes that the data has been lost and asks for it to be resent.


A condition in which a character received is not the one expected. An alignment error usually happens when a character is lost or when a timeout error occurs.


An error in which an asynchronous character is received with an invalid start or stop bit. If this error occurs and the computer is unable to establish a remote access connection, the computer-to-modem (DCE-to-DTE) bps rate may be incorrect. This problem suggests that the modem configured for remote access may not be correct for the modem you're using. Changing the bps rate or the hardware flow control setting may alleviate the problem. Contact your system administrator if this error occurs continually and if you are unable to connect through Dial-Up Networking.


The number of times the sending computer has transmitted characters faster than the receiving computer can process at the hardware level. If this problem persists, reduce the bps rate.


The number of times the sending computer has transmitted characters faster than the receiving computer can process at the software level. If this problem persists, reduce the bps rate or lower the CPU load on the computer.


Resets the statistics for this connection to zero


Displays details about the network connection for the device.


Click to hang up the connection.


The text sent from the local modem to the computer when the modems have finished negotiating. The text typically begins with the word CONNECT, often followed by the status of negotiated features and line speed. For example, the text might show that V.42 bis is in use. This section will be empty if you are using an ISDN line. Refer to your modem documentation for a specific interpretation of the response.


The number of bytes received by the device before the bytes have been decompressed.


The number of bytes sent by the device after the bytes have been compressed.


You can see which networks and devices on your computer are connected, and which users are connected to them.


Displays details about the network connection for the device.


Click to hang up a connection.


You can configure your computer to play sounds to communicate the following connection messages.


Select this check box to hear a sound when a connection is successful.


Select this check box to hear a sound when a connection is dropped.


Select this check box to hear a sound when data is transmitted.


Select this check box to hear a sound when an error occurs.


Select this check box to see a button for the Dial-Up Networking Monitor icon appear in the taskbar after Networking Monitor is started.


Dial-Up Networking Monitor can be configured to show status lights in two forms, as an icon or as a window on the desktop.


Select this check box to see status lights in the Dial-Up Networking Monitor icon next to the clock in the taskbar.


Select this check box to see status lights in the Dial-Up Networking Monitor window on the desktop.


Select this check box to see the title in the Dial-Up Networking Monitor window.


Select this check box to have the Dial-Up Networking Monitor window always appear on top of other windows.


Click to choose which devices on your computer should show status lights.


Click to immediately apply your changes in Dial-Up Networking Monitor.


Select this check box to control how much space the lights take up in the Dial-Up Networking Monitor window.


Select the devices on your computer for which you want to see status lights.


The selected device or connection.


The protocol the device is using for connection.


Lists the address assigned to the computer by the dial-up server. The Address will be displayed only for the protocols enabled for dial-out connections.


The IP address for the RAS server.


The IPX network number assigned to the computer by the dial-up server.


The IPX node identifies a particular computer.


Your computer name.


You can assign more that one phone number to each entry in Dial-Up Networking. This is useful if you have a pool of phone numbers to connect to.

To add additional phone numbers to an entry, type a new phone number and click Add.


Click to add an additional phone number to an entry.


Click to replace the phone number selected in the Phone numbers box with a new one.


The list of additional phone numbers for an entry.


Click to raise the order of the selected phone number in the Phone numbers box until the phone number is in the correct order.

Dial-Up Networking dials the numbers in order until a connection is made.


Click to lower the order of the selected phone number in the Phone numbers box until the phone number is in the correct order.

Dial-Up Networking dials the numbers in order until a connection is made.


Click to delete the selected phone number from the Phone numbers box.


Select this check box to move phone numbers that connected successfully to the top of the list. The next time you dial the phonebook entry, these numbers will be tried first.


Prefixes allow you to add extra numbers to the beginning of phone book entries.

To add a prefix to the list of available prefixes, type a prefix in the box and click Add.


Click to add a new prefix to the list of available prefixes.


Click to replace the prefix highlighted in the Prefixes box with a new prefix.


The list of available prefixes.


Select a prefix and then click to move the prefix up until it is in the correct order.


Select a prefix and then click to move the prefix down until it is in the correct order.


Select a prefix and then click to delete it.


Suffixes allow you to add extra numbers to the end of phone book entries.

To add a suffix to the list of available suffixes, type a suffix in the box and click Add.


Click to add a new suffix to the list of available prefixes.


Click to replace the suffix highlighted in the Suffixes box with a new prefix.


The list of available suffixes.


Select a suffix and then click to move the suffix up until it is in the correct order.


Select a suffix and then click to move the suffix down until it is in the correct order.


Select a suffix and then click to delete it.


Choose a location from which to dial.


Click to add a new location. You can then choose this new location in the Dialing from box in the Dial-Up Networking dialog box.


Prefixes allow you to temporarily add extra numbers to the beginning of all phone book entries without changing every entry.

Choose a prefix to use for the selected location.


Click to add a new prefix.

The prefix list is specific to each user on the computer.


Suffixes allow you to temporarily add extra numbers to the end of all phone book entries without changing every entry.

Choose a suffix to use for the selected location.


Click to add a new suffix.

The suffix list is specific to each user on the computer.


Type the name of a new location in the box.


Click to add the new location to the list of locations.


Click to replace a selected location in the Locations box with the new name.


The list of possible locations for your computer.


Select a location and click to delete it.


Screen text is good enough. Maybe one wording change though - "The Close on dial option hides the phonebook (can we say Dial-Up Networking instead?) while dialing and closes it as soon as you connect."


Select this check box if you do not want to use a script or terminal before dialing.


Select this check box to use a terminal box before dialing.

See Using RAS Terminal for Remote Logons


Select this check box to use a script before dialing.


Select which script to use before dialing. These scripts are part of Switch.inf, in which you can modify or create new scripts.

See Automating Remote Logons Using SWITCH.INF Scripts


Click to instantly access  Switch.inf in order to modify or create new scripts.


Click to update the script list box after editing Switch.inf.


Select this check box to use other ports of the same device type if the device specified in Dial using box is not available. For example, if "Standard modem (COM1)" is selected in the Dial using box and this check box is selected, the modem on COM2 will be automatically used if the COM1 modem is busy.

Clearing this check box is useful for determining what is wrong with the first device when multiple devices are configured.


RAS is trying to reconnect a failed link. You can set this feature in Dial-Up Networking by clicking More and choosing User preferences. In the Dialing tab, clear the Redial on link failure check box.

RAS Autodial must be running for this feature to work. To start Autodial, in the Services icon in Control Panel, double-click Remote Access Autodial Manager. Select Automatic or Manual startup types and click OK. Then click Start in the Services dialog box.


Select this check box to enable the redial on link failure feature, which causes a link to be automatically reconnected when it fails. This feature works only when the Remote Access Autodial service is running.

To start the Autodial service, in the Services icon in Control Panel, double-click Remote Access Autodial Manager. Select Automatic or Manual startup types and click OK. Then click Start in the Services dialog box.


You can choose whether or not the connection is always connected or is brought up as needed. Click to specify a persistent connection. This means that as soon as the service starts, it will keep trying to make a connection.


You can choose whether or not the connection is always connected or is brought up as needed. Click to specify a demand-dial connection. This means that a connection is initiated when there is data to be sent and the connection is closed when there is no data to be sent over the link.


Specify the number of times to automatically redial the number. Specify zero for no redial.


Specify the number of seconds to wait before automatically redialing. This gives the remote device time to reset.


Specify the amount of idle seconds before a connection hangs up.

Keep in mind that the dial-up server also has a disconnect timer. If this control is set to a high timeout number, there is no guarantee that the connection will not disconnect before the time passes. This is because the server may choose to disconnect you before the time set here.

The Remote Access Autodial service must be running in order for this option to take effect.


Click to configure callback options if you want the remote router to call you back after you dial. The remote router must support callback and must have enabled your dial-in account with callback privileges.


HID_RD_RB_MultipleLines

This may get added later.


Select this option if you do not want the dial-up server to call you back.


Select this option if you want the remote router to call you back. You must then supply phone numbers for each device


Select the device to be used during callback and click Edit to enter a phone number.


Click to enter a phone number for the remote router to use when calling your back.


Click to delete the selected device from the callback list.


broadcast

Destined for all hosts on a given network.


multicast

Destined for a set of hosts that belong to a multicast group.


unicast

Destined for a single host.


Internet service provider.


56K, T1, or Frame Relay


modem or ISDN


A proxy server acts as a security barrier between your internal network and the Internet, keeping other people on the Internet from gaining access to confidential information on your internal network.


Wide Area Network


Point to Point Tunneling Protocol

A powerful TCP/IP protocol that allows you to use the entire Internet as a router to communicate with your office network.


Internet service provider.


56K, T1, or Frame Relay


modem or ISDN


A proxy server acts as a security barrier between your internal network and the Internet, keeping other people on the Internet from gaining access to confidential information on your internal network.


Wide Area Network


Local Area Network


Refers to rules that prevent routing loops. Information about a route is not sent back toward the source of the information.


Used with split horizon. Split horizon with poison reverse improves RIP convergence over simple split horizon by advertising all network IDs, but those network IDs learned in a given direction are advertised with a hop count of 16, indicating that the network is unavailable.