Question about ip cef?

[rbinc]

I am currently using bgp with two different ISPs. I was under the impression that i could "load balance" outbound traffic with cef? I thought if i enabled it, I could do a per session load balance.

Is this incorrect?

thanks!

-J

[Harold Ritter]

CEF per prefix load balancing will only work if you have two or more paths installed in the RIB for a given prefix. For that to happen you would need to use BGP multipath feature. The problem is that this feature requires the prefixes to be from the same neighboring AS in order to consider them equal.

If you receive full routing table from your ISPs, you can just let BGP make its best path decision on each and every prefix, which usually will lead to somewhat equal load balancing assuming that your ISPs are equally well connected to the Internet.

Hope this helps,