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Matt_70198's avatar
Matt_70198
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Feb 09, 2012

Trunk to two separate switches?

We have two separate HA production switches, Sw1 and Sw2, with an etherchannel between them. We'd like to have redundant links to the LB so we have 1 link from Sw1 to LB 1.1, and 1 link from Sw2 to LB...
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Matt_70198's avatar
Matt_70198
Icon for Nimbostratus rankNimbostratus
Feb 09, 2012
Correct no ability to etherchannel the switchports going to the LB.

 

 

A coworker steered me down the wrong path by saying I need to do this with a trunk and not selecting LACP. I did what you suggested nitass and removed the trunk and added 1.1 and 1.2 to External vlan.

 

 

 

With STP in pass-through I see Sw2 Gi1/0/6 in BLK. With STP enabled on the LB I see 1.1 in FWD and 1.2 in BLK.

 

 

 

During testing I found pass-through doesn't work so well, I shut down 1/6 on Sw1 and instead of Sw2 1/6 going to FWD it went to block loop inconsistent state for some reason, had to shut no shut interface for it to come up.

 

 

 

With LB mode set to STP I shut down Sw1 1/6, 1.1 went to BLK, 1.2 went to FWD, all was good. So in this type of setup STP is preferred vs pass-through.

 

 

 

Thanks for the advice nitass!