[c-nsp] FHRP's and STP

[Phil Mayers]

Kevin Graham wrote:
> Is there a way to (safely) force any of the FHRP's into a multiple-active setup
> such that the first router to see a packet can route it? Namely, I'm frustrated
> by instances w/ L3 switches where the L2 topology (via STP) doesn't match the
> L3 topology (via a FHRP) resulting in cases where traffic gets L2 switched by a
> FHRP standby on its way to the active router only to get punted back again.

This is an annoying outcome, but would you not be better concentrating 
on ensuring the STP topology matches the desired FHRP topo?

> 
> A tracking object based on STP state would probably be sufficient, though being
> able to assign multiple routers to an active forwarding group seems ideal. Am I
> missing something obviously?

I don't believe any of the FHRPs can do what you want - even GLBP works 
(as I understand it) by answering ARP requests for the gateway with 
different vmacs, and a router will only route vmacs it owns locally.