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New Member

Proble in Spanning tree over L2 inks




 I am facing problem in spanning tree over L2 link.please find the digram for your understanding.


  1) we have two 4500 switches in my HO as a core there are two links are connected between them & configured as a port channel.

    2) We have some server which are co locate in nearest DATA center to access that server from HO we have two L2 link between Ho & DATA center

   3) but we are facing issue in spanning tree at the end of HO switch port stat is showing forwarding state in Active switch as well standby switch & in DATA center we are facing the same problem,

     is there any challenges for spanning tree over L2 links?

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

Are all the interconnects

Are all the interconnects trunk links ?

If so please pick one vlan that is allowed on all the trunk links and from each switch post a -

"sh spanning-tree vlan <x>"  for that vlan.


New Member

"spanning tree at the end of

"spanning tree at the end of HO switch port stat is showing forwarding state" -- it may not be an error, check spanning tree status of the interfaces connecting switches. The port may have been blocked on other switch.


Possibly check : Show Spanning-tree