I was wondering if my switch that doesn't have MAC addresses assigned to any of its customer ports can even pareticipate in spanning tree protocol negotiations?


Switches don't normally have MAC addresses assigned to the access ports because switches are transparent devices. The switch itself has one or more MAC addresses internally that it will use for things like STP.

If this is a layer-3 switch, and you can change an access port into a router port, then the switch supervisor will assign a MAC address to the port.

  • Thank you, and hence the answer to my question is, yes it can, correct?
    – stdcerr
    Nov 5 '16 at 15:08
  • But even if the switch just lives in L2 land, will it still be able to properly participate in STP?
    – stdcerr
    Nov 5 '16 at 15:14
  • STP is a layer-2 protocol. Layer-3 devices/ports don't participate in STP.
    – Ron Maupin
    Nov 5 '16 at 15:16
  • Yes, this was just in regards to the paragraph in your answer that starts with "If this is a layer-3 switch..." - even if this switch is not a L3 router/switch, it will be able to do STP (independent of the Mac it may or may not get assigned)
    – stdcerr
    Nov 5 '16 at 15:20
  • A layer-3 switch is still primarily a layer-2 switch. The layer-3 part is just a routing module, and that and any ports set to be layer-3 ports do not participate in STP. The layer-2 ports will participate.
    – Ron Maupin
    Nov 5 '16 at 15:22

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