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New Member

Cross Stack Etherchannel for 3750 12S


I am looking at an issue with a cross stack etherchannel running LACP. Member port g1/0/1 of the bundle is changing state frequently without any known cause.

The two stacks are made of 1x Cisco 3750 12S and 1x Cisco 3750 E 24.

G1/0/1 on the 12S connects to G1/0/1 on the other 12S SFP.

G2/0/1 on the E connects to G 2/0/1 on the other E using copper.

Interface G1/0/1 is flapping. Bundle is active and passing traffic.

Anyone seen this combination?

Everyone's tags (1)
Hall of Fame Super Gold

Re: Cross Stack Etherchannel for 3750 12S

Have you changed the Gi1/0/1 fibre optic cable and/or SFP that connects the two 3750G-12S?

VIP Super Bronze

Re: Cross Stack Etherchannel for 3750 12S

I agree with Leo,

You may have a bad fiber patch cable or a bad SFP.


New Member

Re: Cross Stack Etherchannel for 3750 12S

Thanks for the advice.

I had changed the SFP and the Fibre cabling. I eneded up having to move the link to an alternate slot on the 12S.

Might need to get a TAC raised.

Thanks again.