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Routing and Remote Access Service with a Null Serial Cable
ID: Q172189
 
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The information in this article applies to:
- 
Microsoft Windows NT Server version  4.0
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Microsoft Routing and Remote Access Service Update for Windows NT Server 4.0
SUMMARY
The information in this article explains how to setup a Dial-on-Demand
(DOD) connection between two Routing and Remote Access Service (RRAS)
Servers using a null serial cable.
MORE INFORMATION
The following steps assume that you have already installed Routing and
Remote Access Service and that it is operating correctly. Perform the
following steps on both servers:
- Click the Start button, point to Settings, click Control Panel, and
   then double-click the Modems icon.
- Click Don't detect my modem; I will select it from a list and click
   Next.
- Click Dial-Up Networking Serial Cable between 2 PCs, and then click
   Next.
- Click the physical com port to which the cable is attached, and then
   click Next.
 
 NOTE: If this is the first modem that you have installed you will now
   need to enter the area code and any dial out prefix that is required.
- Restart your server.
- Click the Start button, point to Settings, click Control Panel, and
   then double-click the Modems icon. Verify the modem properties on both
   servers and make sure the maximum speed matches.
 
 NOTE: It is best to start at 9600 bps and increase it later to a
   speed that does not give serial overruns. Each time you change the
   speed, you will need to stop and restart Routing and Remote Access
   Service for the change to take effect.
- Start Routing and Remote Access Service Administrator and add a DOD
   interface on both servers, using the following steps:
- Click LAN and Demand Dial Interfaces.
- Click Actions, click Add Interface..., and then type the name for your
      DOD connection. For the sake of simplicity, use the same name on
      both servers.
- Click Next.
- Click the appropriate routing options to enable them.
 
 For example, if you are using Routing Information Protocol (RIP) for
      IP then you would enable the option Route IP packets on this
      interface.
- Click the following options to create the user accounts:
- Add a user account so a remote router can dial in
         Authenticate remote router when dialing out
- Click Next, click Dial-Up Networking Serial Cable between 2 PCs
      (ComX), and then click Next.
 
 where X is the com port number.
- Leave the phone number blank, and then click Next.
- Enter the same name that you used in step b for the User Name,
      Password, and Confirm Password.
- Click Next and type the same name as steps b and h for the Password
      and Confirm Password.
- Click Next, and then click Finish.
- Click the desired routing protocols, and then accept the default
   options.
- Once both DOD Interfaces are created, from one server only in Routing
   and Remote Access Service Administrator, click LAN and Demand Dial
   Interfaces. Right-click on the new DOD interface, and then click
   Connect.
At this point your two servers should be connected through the null serial
cable. When you use DOD connections with Routing and Remote Access Service
the routes are not automatically updated so you have to manually update
any routes by performing the following steps:- In Routing and Remote Access Service from both servers, expand IP
   Routing and/or IPX Routing depending on which routing protocols you
   have installed.
- Click Summary, right-click the DOD interface, and then click Update
   Routes.
- Click Static Routes, and if the routes were exchanged successfully, you
   should see the routes from the opposite server.
Troubleshooting
If you are experiencing problems connecting or exchanging routes between
the two servers, check for one or more of the following:
- Check the modem properties and verify the Maximum Speed for the Serial
   Cable connections match on both servers.
 
 -or-
- From both servers, verify the Initial Speed setting by performing the
   following steps:
- In the Routing and Remote Access Service Administrator, click LAN
      and Demand Dial Interfaces.
- Right-click the new DOD interface, and then click Configure
      Interface.
- Click Configure, and verify that Initial Speed matches the Maximum
      Speed in the modem properties, and that these speeds match the other
      server.
 
 NOTE: It is imperative that if you make any changes to the modem
      properties, Routing and Remote Access Service must be stopped and
      restarted.
-or-
- If both servers seem to be connecting successfully but cannot exchange
   RIP routes or clients on either side of the routers cannot communicate
   but the servers can, then check to see if a RAS connection was made
   instead of DOD using the following steps:
- In the Routing and Remote Access Service Administrator, click LAN
      and Demand Dial Interfaces.
- Verify that the Connection State for the DOD interfaces are
      displaying Connected.
 
 NOTE: If only the dialing computer shows connected, then, most
      likely, a RAS connection has been made. If this is the case, check
      to see that the User Name being used in the credentials on the
      dialing server matches the name of a DOD interface on the server
      being dialed.
Additional query words: 
modem interlink cross-over laplink steelhead dial on demand 
Keywords          : kbnetwork kbhowto nthowto ntnetserv kbinfo ntrouter NTSrv 
Version           : WinNT:4.0
Platform          : winnt 
Issue type        : kbinfo 
Last Reviewed: February 24, 1999