[nsp] EtherChannel

[Lars Erik Gullerud]

On Mon, 2003-12-01 at 15:03, Olav Langeland wrote:

> The part with XOR'ing and what could be load balanced or not went a bit
> over my head, I have not read the finer details about EtherChannel
> loadbalancing. Question still is, will it work? Setup is Cisco 7513 <-
> EtherChannel -> Catalyst switch with 2 or more FastEthernet ports. I
> don't want to do anything fancy, just to make the total bandwidth
> available for the router more than 100Mbit, even though if one stream is
> limited to max 100Mbit.
> Will this work efficiently and can it be used in an ISP environment?

The part about XOR'ing etc. has to do with load-distribution over the
bundled links. In an EtherChannel this is not a per-packet type
distribution, but rather using a MAC-based hash. The Cat3524XL's can be
set to "destination" or "source" modes only. Since all traffic in one
direction will in this scenario be going to a router (i.e. just one
MAC), setting this bit wrong will in fact give you no load-balancing at
all, since everything will have the the same destination-MAC (the
router's MAC).

Other than that it should work - of course you may have other issues if
you are trying to do this on say, two PA-FE cards in a VIP2, which would
probably run into load issues with this amount of traffic.

Personally I'd stick a GEIP+ in the box instead, which shouldn't cost an
arm and a leg to get secondhand these days either.

/leg