Query on debug ip packet detail ouput

arun.mallappally123 · ‎02-06-2013

Hi,

While I am debuging ICMP traffic originated from a router ( Debug ip packet details) it is showing packets routed via FIB and reply is showing as routed via RIB .is it means ICMP packet originating from the router is CEF switched ? if it does then whether the CEF switched packet will show in the debug output ?.Documents showing that only process switched packet can be debugged .

one more doubt regarding the routing process

documents stating that the routing process is actually consist of three processes 1.routing 2.switching 3.encapsulation

so regardless of every switching methods (Process ,Fast or CEF ) router is doing routing table lookup in the first process (Routing) ?

thanks

Arun Mohan

cadet alain · ‎02-06-2013

Hi,

Process switching : route lookup for every packet

Fast switching: route lookup for first packet then use the fast switching cache for next packets going to same destination

CEF: the FIB is prebuilt from the RIB and the router uses FIB to forward packet

Regards.

Alain

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