ip route-cache / fast switching
March 11th, 2010
“ip route-cache” controls the use of switching methods for forwarding IP packets:
ip route-cache [same-interface | flow | distributed | cef | policy]
- same-interface – Enables fast-switching packets to forward IP packets back out through the interface on which they arrived.
- flow – Enables NetFlow accounting for packets that are received by the interface.
- distributed – Enables distributed switching on the interface.
- cef – Enables Cisco Express Forwarding (CEF) operation on an interface.
- policy – Enables fast-switching for packets that are forwarded using Policy Based Routing (PBR).
Do you have “no ip route-cache” configured but are still apparently fast switching? Possibly because the “show int switching” command does not at the time of writing distinguish between fast-switched and CEF-switched packets, so CEF-switched packets are recorded as being fast-switched.
“show adj detail” Will show how many packets/bytes are CEF switched out of each next-hop/adjacency.
