Cisco IOS Cookbook, 2nd Edition

Debugging DSLw

Problem

You want to debug and isolate DLSw problems.

Solution

The first thing to do with any DLSw issue is verify that the peers are working correctly, as in Recipe 15.13. If the peers are not established, then test IP connectivity with PING packets. If you can PING but the peers won’t come up, then verify your configuration, as in Recipe 15.2. Ensure in particular that the remote-peer of each router precisely matches the local-peer of the other end.

If the DLSw peers are active, check the circuits, as in Recipe 15.13.

For failed circuits involving SDLC devices, check the interface, as in Recipe 15.14.

For Token Ring or Ethernet devices, verify that the interface is functioning properly as in Chapter 16.

If the peers are active and the interfaces look good, then there are three main things that could still be wrong. There could be a loop problem within the DLSw network. There could be a MAC address problem or a MAC or LSAP filtering issue. Or there could be a network congestion or performance problem.

There are several useful debug commands for use with DLSw. For looking at the router-to-router DLSw transport, you can use the debug dlsw command:

dlsw-branch#debug dlsw

You can get other useful information about SNA and LLC2 connection problems with these debug commands:

dlsw-branch#debug sna state
dlsw-branch#debug llc2 state

Discussion

If your routers will not establish a DLSw peer relationship, the most common problem is simple IP connectivity. Verify that you can PING the address ...