Re: Etherchannel Issue

Hi,

On Sun, May 24, 2009 at 2:24 PM, qospf qospf <cisco.qospf_at_gmail.com> wrote:
> another silly question on that note. If I'm creating port-channels basically
> in a "square" shape with 4 switches (i.e. Sw1 has 2 ports to Sw 2 and 2 to
> Sw3, Sw3 has 2 to Sw 1 and Sw4 and so on...). Is it necessary, to create a
> different channel group for each link? can we name the links b/w the two
> different switches to be "channel-group 1".

Use a unique channel-group number for each set of switchports going to
the same switch. Group numbers are only locally significant, though,
so you could have something like:

 SW1's two ports to SW2 = channel-group 12
 SW1's two ports to SW3 = channel-group 13
 SW3's two ports to SW1 = channel-group 47
 SW3's two ports to SW4 = channel-group 34
 SW4's two ports to SW3 = channel-group 43
 SW4's two ports to SW2 = channel-group 12

(I would recommend coming up with a convention and sticking to it --
it gets confusing otherwise.)

If channel-group A on SW1 had member links going to different bridges
(SW2 and SW3, for example), you would create an interesting
spanning-tree situation. At best, your links would be disabled. At
worst, you'd melt the network -- depends on the rest of your config I
guess.

cheers,
Dale

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Received on Sun May 24 2009 - 14:41:34 ART