Verifying and Troubleshooting

Verifying and Troubleshooting
Policy-Based Routing Operation
After implementing policy-based routing, you need a way to verify that it is operating properly, and
if it is not, then you need to be able to troubleshoot it. That’s what will be covered in this section.
334 Chapter 10  Route Optimization
The show ip policy command lists all the interfaces configured for policy-based routing
and their associated route maps:
R1#show ip policy
Interface Route map
FastEthernet0/0policy3
Serial0/0.1 policy2
Serial0/0.2 policy1
Serial0/0.3 policy2
From the preceding output, you can determine which interfaces have policy-based routing
enabled and which route map is enforcing the policy. After you have determined the interfaces
that have policy-based routing enabled, you can view the contents of the route map that is
enforcing the policy. You can view all the route maps on the router with the command show
route-map:
R1#show route-map
route-map policy1, permit, sequence 10
Match clauses:
ip address (access-lists): 1
Set clauses:
ip next-hop 192.168.10.1
Policy routing matches: 0 packets, 0 bytes
route-map policy1, permit, sequence 20
Match clauses:
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map policy2, permit, sequence 10
Match clauses:
ip address (access-lists): 2
Set clauses:
ip next-hop 192.168.20.1
Policy routing matches: 0 packets, 0 bytes
route-map policy2, permit, sequence 20
Match clauses:
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map policy3, permit, sequence 10
Match clauses:
ip address (access-lists): 3
Set clauses:
ip next-hop 192.168.30.1
Verifying and Troubleshooting Policy-Based Routing Operation 335
Policy routing matches: 253 packets, 27965 bytes
route-map policy3, permit, sequence 20
Match clauses:
Set clauses:
Policy routing matches: 0 packets, 0 bytes
The preceding output informs you what is being used as the match condition and, if a match
is made, what the set condition is. The output also provides you the number of matches for a
sequence of the route map.
The debug ip policy command can be used to determine what policy-based routing is
doing. This command provides you with information on the packets that were matched and the
related routing information. It also informs you when a packet doesn’t match.
Consider the network in Figure 10.6.