I am sure this is a common question but would like to know the best practices. I have a pair of Juniper routers connecting to a IRFed HP 10k core switch. My HP core runs stp and we are tyring to extend the L2 of HP core to router as well, for that we would need to enable the rstp on the Juniper mx routers.

Does RSTP and STP on core works well or do we need to move to rstp on the core as well?

  • 2
    Can you provide a diagram of your network? Normally routers don't run spanning tree.
    – Ron Trunk
    Jan 9, 2017 at 1:43
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 15, 2017 at 4:18

1 Answer 1


We're talking about two different versions of spanning-tree, IEEE 802.1D STP standard and IEEE 802.1W RSTP, they cannot work together because 802.1D does not understand RSTP BPDUs, but when a RSTP Switch receives an 802.1D BPDU, it responds with 802.1D BPDU and eventually the two switches runs 802.1D to communicate.
The best practice is to configure RSTP on all Switched environment.

I don't understand the need of spanning-tree on the routers, they never cause a layer 2 loop.

  • Some routers allow ports to be configure as switch groups which may require xSTP.
    – Zac67
    Apr 15, 2021 at 13:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.