Nexus VPC Extension - facing STP loop

[desiderata]

Attn: Sergiu.Daniluk

Hi,

Reference discussion: https://community.cisco.com/t5/data-center-switches/nexus-vpc-extension/m-p/4545745/thread-id/7998

I have attached configuration files of 6 switches here. 

Whenever I am turning ports from NX 3 and 4 (connected with core switches) up, a STP loop is occurring between vpc domain 1 and 12. I have attached screenshot of few logs from N9K-1, N9K-2, Core1 and Core2 switch.

Can you please help with any possible suggestion to avoid this loop? 

Thanks in advance.

[desiderata]

Hi,

Connectivity diagram is attached herewith. According to the diagram, Whenever I am turning ports from NX 3 and 4 (connected with core switches) up, a STP loop is occurring between vpc domain 10 and 11.

Please ignore previous statement.

[Sergiu.Daniluk]

To have the full picture, please add port-channel numbers on the diagrams and share the config files again (they are missing from first post).

Cheers,

Sergiu

[desiderata]

hi Sergiu,

Many thanks for your response.

Kindly find attached connectivity diagram including Po numbers. I'll be attaching necessary config in a separate reply.

[desiderata]

Hi,

Sorry for the inconvenience. Please check attached config files.

[desiderata]

Hi,

Few things I should mention:

• Core1 and Core2 switches are also acting as distribution switches, I mean, few servers are directly connected from core switches. The logs I have shared from these switches, contains port-channel numbers of those servers (i.e., Po88, Po92, Po99 etc.). If you need, I can share all vPC and port-channel list from these two switches.
• Same vPC numbers have been used from VPC domain 10 and 11, for different purpose, i.e., vPC number 108. This should not be an issue, right?

For your better understanding, I have attached an updated diagram.

[desiderata]

Hi Sergiu,

Any suggestion please? 

[Bernd Nies]

Isn't the vPC supposed to go across both switches - i.e. combine the port-channels on both switches in the same vPC domain?

[sp2720401]

You are correct. 

In the above super pretty image I attached. You would have port-channel red and port-channel blue... Then you would have vpc red and vpc blue.