Switching

[Waheed Eladawy]

 thanks,

[balaji.bandi]

what model of the switches ? This looks for high level based on information, spanning-tree issue. or this is stack cabling issue.

Can you make a small Diagram and post here how these were connected and good to have configuraiton also.

[Waheed Eladawy]

   thanks for ur reply 

[balaji.bandi]

When you get chance take paper and write small diagram to understand better.

also post all relevant config tp assist better.

[paul driver]

Hello

Looks like ariuba /hpe switch?

First of all ports dont necessary auto shutdown if unplugged and re-attached however , they could err-disable due to udld or spanning-tree with the latter could also cause a network stp recalculation as such the uplinks were were temporary disabled until the network re-converge

Does  trk3 reside the access stack connecting to the core, if so change the stp priority to 15 if its the core trk change it to 0 or 1

[Georg Pauwen]

Hello,

so you have two stacks, connected through a port channel ? Not really sure if I fully understand your setup either, but with LACP, keep in mind the below:

--> With LACP, the system-id uses the stack MAC address from the stack master, and if the stack master changes, the LACP system-id can change. If the LACP system-id changes, the entire EtherChannel will flap, and there will be an STP reconvergence. Use the stack-mac persistent timer command to control whether or not the stack MAC address changes during a master failover.