Gig Etherchannel loadbalancing

alanwright1 · ‎04-12-2007

Hi Folks,

I am trying to understand how the algorithm for Etherchannel load balancing works. If is select port-channel load-balance src-ip and i have say 4 channel members (g1/0/1,g1/0/2,g1/0/3,g1/0/4) lets assume that IP1 goes to g1/0/1 when all are active. If g1/0/4 goes down, will IP1 still remain on g1/0/1 or will it be re-assigned? The question really is whether the traffic assigned to a link will be remain on the link if another member fails?

TIA

Alan

mahmoodmkl · ‎04-12-2007

Hi

I will be automatically swithced to other link.

Thanks

Mahmood

alanwright1 · ‎04-12-2007

Hi Mahmood,

So you are saying that there will be a global re-assignment within the etherchannel if any member fails?

Thanks

Alan

pciaccio · ‎04-12-2007

Alan:

The EtherChannel Frame distribution hashing algorithm performs an XOR operation on one or more low-order bits of the addresses. For a 2 port bundle the last bit is used. For a 4 port bundle the last two bits are used. For an 8 port bundle the last 3 bits are used. If a link fails then the traffic will move to the remaining links. Hope this helps.. Please rate...

alanwright1 · ‎04-12-2007

Assuming I started with a 4 port bundle, one member subsequently failed (3 remaining), would it still XOR on the last two bits?

Also in the XOR, does the IP XOR with the channel member number?

Thanks

Alan