Problems Clearing and Adding To Routing Tables Using ROUTE.EXE

• Microsoft Windows NT operating system version 3.1
• Microsoft Windows NT Advanced Server version 3.1
• Microsoft Windows NT Workstation versions 3.5 and 3.51
• Microsoft Windows NT Server versions 3.5 and 3.51
• Microsoft TCP/IP-32 for Windows for Workgroups versions 3.11

SYMPTOMS

You may experience problems configuring static routing tables in Windows NT and TCP/IP-32 for Windows for Workgroups when using the following ROUTE.EXE commands:

   ROUTE -F      (clears routing tables for all gateway entries)
   ROUTE ADD     (adds a route to the routing tables)

ROUTE -F

On a multihomed computer, the default gateway IP addresses of 0.0.0.0 for all network interface cards (NICs) are lost when you use the ROUTE -F command.

If you add the default gateway using the ROUTE ADD command, the default gateway route for only the first NIC is applied. The default gateway routes of 0.0.0.0 for other NICs are lost.

ROUTE ADD

If you use the ROUTE ADD command and add an incorrect entry, the entry is not added to the route table. No message is displayed indicating that the entry is incorrect and has not been added.

MORE INFORMATION

The correct format for the ROUTE ADD command is:

   route add <subnet address> MASK <subnet mask> <address to add>

STATUS

Microsoft has confirmed this to be a problem in Windows NT versions 3.1, 3.5, and 3.51 and in TCP/IP-32 for Windows for Workgroups version 3.11. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.