STP root-port selection can be a client(server)?

[eeebbunee]

Hello Professionals!

I am trying to re-arranging VLANs / STP protocol of my switches but I found something that weird.

When I do>> sh spanning-tree root

I can see all of root port of each VLANs.

Weird thing is that VLAN001 is pointing Gi2/0/46 as a root port, but Gi2/0/46 is connected to end device. (Server).

Switch can select the end device as a root port? How?

Thank you.

[MHM Cisco World]

Server is run VM ?

[eeebbunee]

Yes, server is running for hypervisor and VM. 

VM could be the reason..?

[MHM Cisco World]

Yes, as I know the vSwitch can some times forward BPDU from one port to other.
you can debug the BPDU and see if it source mac of  BPDU is mac  of other SW port or not.

[Reza Sharifi]

The Hypervisor has a vSwitch but STP usually is not implemented on vSwitches.

HTH 

[MHM Cisco World]

Yes STP not run in vSwitch but vSwitch can forward BPDU from port to port, 
this make SW see BPDU from port connect to Server. 
this my opinion of this case,
thanks 
MHM 

[paul driver]

Hello
You could apply spanning-tree bpdufilter enable on the port connecting to the server, but this opens you up to for that port to be potentially used for another switching device, so you need to make sure that doesn't happen