White Papers

21 Using Policy Based Routing and Access Control Lists in a Virtualized Network
6 Rerouting Remaining Packets on an Interface
If there is a need to route any remaining packets on an incoming interface, it can be done with PBR. This
is achieved simply by not specifying a match statement in the route-map sequence. If used by itself
without other sequences, this can also be used to re-route all incoming traffic.
Note: In a route-map sequence, all packets match by default if no match statement is specified.
This can be useful as a lowest priority sequence to send all remaining traffic through a particular route if
no higher priority sequences were matched.
Using Example 1 above, the route-map only matches packets from two groups (hr and accounting) on the
network. If there are more groups, they will use traditional routing since there is no route-map matching
critera for those packets. However, if it is desired that all other traffic be routed along a third path, then a
third sequence (i.e. 30) can be used. The third sequence does not require a match statement since the
desire is that all packets not matching sequence 10 or 20 are routed through a third next-hop.
Consider the following commands taken from Example 1. By adding a few more commands, the
remaining traffic can also be policy routed.
The existing sequences from Example 1 are…
console(config)#route-map equal-access permit 10
console(config-route-map)#match ip address accounting
console(config-route-map)#set ip default next-hop 192.168.6.6
console(config-route-map)#exit
console(config)#route-map equal-access permit 20
console(config-route-map)#match ip address hr
console(config-route-map)#set ip default next-hop 172.16.7.7
console(config-route-map)#exit
Add the following to route all remaining packets along a third path…
console(config)#route-map equal-access permit 30
console(config-route-map)#set ip default next-hop 175.10.8.8
console(config-route-map)#exit
All incoming packets that do not match sequence 10 or 20 are now policy routed with a next-hop of
175.10.8.8.