channel-group on 2 switches

[Sam Sanders]

I have 2 Catalyst 3560 24-port switches (call them switch-a and switch-b).  They are linked together with a patch cable and not stacked (the c3750 is stackable but not the c3560). Is it possible to have a port-channel group with 2 ports, where one port is on switch-A and the other one is on switch-B?  If not, is it possible if the 2 switches were stackable like the c3750 switches?  Many thanks in advance.  -Sam

[ghostinthenet · Accepted solution]

Hey Sam:

Stacking, in the sense used by the 3750 switches, and channel groups really don't have anything to do with one another. Obviously the 3560 can't stack in that sense, but channel groups are definitely workable on those switches.

However, if you want to split the channel group so that half is on one switch and half is on the other, that will require proper stacking. This definitely works on a stacked set of 3750 switches, but won't be doable on two 3560 units.

Jody

[Joseph W. Doherty]

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Posting

As Jody already noted, 3560 (not stackable) no, 3750 (stackable) yes.

Other Cisco stackables, such as the 3650 series, 3850 series and 2960S (and later) series, also allow port channels across multiple physical switches (when stacked).

But, beyond stackables, you could also have a port-channel across two Cisco physical switches, if they were a VSS pair (one logical device, so much like a stackable) or Nexus pair (two logical devices).  The latter's vPC (virtual port channel), is the "interesting variant", as, in theory (?) it could be implemented on something like a 3560 or other non-stackable switches, but don't hold your breath.  ;)