“If the packets do not meet any of the defined match criteria (that is, if the packets fall off the end of a route map), then those packets are routed through the normal destination-based routing process. If it is desired not to revert to normal forwarding and to drop the packets that do not match the specified criteria, then interface Null 0 should be specified as the last interface in the list by using the set clause.”
http://www.cisco.com/en/US/products/ps6599/products_white_paper09186a00800a4409.shtml
So let us say you are creating a route-map condition where if a certain packet is received by the border router it has to go to a certain router as next-hop. Yes I know, for those guys studying CCNP Route this lab sounds familiar. You initially create your extended access-list: access-list 111 permit tcp any any eq 80
You then create your route-map:
route-map pbr permit 10
match ip add 111
set ip next-hop <to the ip add of the assigned router>
All along I thought you still need to create another route map, let us say sequence 20 without putting any match or set statement just to allow other packets to go through. Apparently according to cisco documentation, this not needed any more. Interesting….