Enabling IP Routing

• Microsoft Windows NT operating system version 3.1

This article describes how to enable IP routing in Windows NT and how to configure static routing tables using ROUTE.EXE.

How to Enable IP Routing

Routing between subnets is disabled by default for the TCP/IP protocol in Windows NT. To enable routing, following these steps:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

1. Start Registry Editor (REGEDT32.EXE) and go to the following subkey:

         HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip
         \Parameters
   

2. From the Edit menu, choose Add Value.

3. Enter the following values:

         Value Name: IpEnableRouter
         Data Type: REG_DWORD
         Value: 1
   

4. Exit Registry Editor and restart Windows NT.

Configuring Static Routing Tables

If two subnets are separated by more than one Windows NT machine or by a router, Windows NT can route between the subnets if you manually configure the routing tables. Static configurable routing is supported, but neither routing information protocol (RIP) or OSPF are supported.

The ROUTE.EXE command manually configures network routing tables. ROUTE has the following syntax:

   route [-fs] [command [destination][gateway]]

Switches

   -f Clears routing tables

   -s Packets for which no destinations are found are routed to the
      smart gateway.

Commands

   add      Adds a route
   delete   Deletes a path
   print    Prints a route
   change   Changes an existing route