CEF Question

[rajesh444]

Hi,

When enabling CEF on a Cisco router, is it necessary to enable it on the individual interfaces as well as globally? From my understanding, FIB/adjacency table information is maintained globally.

Also, if both fast-switching & CEF are enabled, does CEF take precedence on routing decisions?

Thanks,

Rajesh

[robho]

Hi,

When you enable CEF or dCEF globally, all interfaces that support CEF are enabled by default. If you want to turn off CEF or dCEF on a particular interface, you can do so as well.

Great doc regarding CEF is here,

http://www.cisco.com/warp/public/105/loadbal_cef.html

-Robert

[rajesh444]

Robert,

Thanks for the document. You are right, CEF does automatically gets enabled on the interfaces. I have IPSec tunnels terminating on the routers and am concerned about potential impact of enabling CEF on serial interfaces on VPN traffic.

Also, does CEF eliminate the need for MLS on

Layer-3 switches?

Thanks,

Rajesh

Rajesh