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Dual link Ether channel terminating across HSRP Core?

I have a core of 2 x 6509's running HSRP between them, connected via a dot1q Ether Channel link with no VLAN pruning.

Hanging off this core I have a 3rd 6509, this 3rd device is conected with two links, int 1/1 and 1/2.

6509 #3 is configured as such:

set port channel 1/1-2 10

&

#module 1 : 2-port 1000BaseX Supervisor

set port trap 1/1-2 enable

set port name 1/1 Trunk-Core2

set port name 1/2 Trunk-Core1

set trunk 1/1 on dot1q 1-1005,1025-4094

set trunk 1/2 on dot1q 1-1005,1025-4094

Being that the link from 1/1 terminates on Core #2 and the link from 1/2 terminates on Core #1, how can the pair of links, 1/1 & 1/2 be operating as an Etherchannel port group?

This seems to look a lot like Nortel's Split Multi-Link Trunking (SMLT), which I was not aware was a functional capability on cisco equipment.

Thanks in advance.

Cheers, Kirby.

2 REPLIES
Purple

Re: Dual link Ether channel terminating across HSRP Core?

don't think this is possible. Are you sure the channel is actually working? What does a "show port channel" command look like ? Just because the command is in the config doesn't mean the channel is actually working. It is not really a ether channel if you have a single link going to 2 separate boxes . Etherchannel is the aggregation of multiple fiber or copper links to the same box...

Re: Dual link Ether channel terminating across HSRP Core?

port channeling or combining two or more ports to a combined bigger pipe is not supported when the the channel from one device terminates to two different devices. This is not what channeling is supposed to do. You can configured the ports to channel but it will not form channel unless yoo forced them to "on" then channeling will be the least of the problem, if it even formed. Potentially, it will create a loop if the switch is forced to channel from a switch where the two port forcing to channel is terminating to two different devices. You can however, create two separate channels (different channel id, etc) you can connect 1/1 and 1/2 to core1 or core2 and then create another two or more port to core1 or core2 in a separate channel. this does not break the channel rule as they are two separate channel.

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