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?
Best Answer
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.