[c-nsp] IP Cef load sharing, quick question

[Peter Rathlev]

On Thu, 2008-11-13 at 11:50 -0500, Drew Weaver wrote:
> GWIP was substituted for the ip of the 'gateway' or other end of that
> interface.
> 
> Sorry, of course the IP would be in the route. I was just
> 'obfusticating the output' for the list, as they say ;-)

That explains a lot. Overlooked that one. :-)

> As far as the GLBP goes, this solution isn't for any particular L4
> application it is just for all network traffic from any server on this
> switch to the rest of the network.

AFAIK, GLBP would require one L2 segment shared between the three links.
In that case you might not be able to take advantage of it at all. If
you have redundant paths, e.g. if the three destinations in the other
end of the links have L2 connectivity (for this VLAN) other than through
your gateway, then spanning tree or an equivalent might block all but
one link, thus rendering the load sharing part of GLBP less effective.

Making your gateway the STP root would mitigate this, but that might not
be desirable/possible.

I'd keep the ECMP with static routes and no L2 connectivity between the
links and then let CEF do the load-sharing, per destination.

Regards,
Peter