quick switch...

the big difference...

process switching requires cpu involvement with every forwarding decision

fast switching relies on the cpu as well but once a packet is forwarded,

the destination path is stored in fast switching cache.  this allows the

path to be re-used from the cache and precludes a new look up by the cpu

for that path

cef is the next evolution enabling the router to forward packets yet

faster.  it builds a forward information base and an adjacency table.

access is quick because it is bulit into the hardware (asics).  the fib contains

pre-computed reverse lookups as well as next hops, and layer 2

information and the interface to use.