
On a site, I changed the Campus Core with an HP 10504. Many Cisco switches are still connected on the HP (some in daisy-chaining).
RPVST+ is configured on Cisco and RSTP on HP.
RPVST+ is per-vlan and RSTP is per-instance. Seems to be compatible but not sure.
I was wondering how the spanning-tree protocol deals with such a change.
[HP]dis stp root
MSTID Root Bridge ID ExtPathCost IntPathCost Root Port
0 4096.b8af-6763-e67e 0 0
HP is the root bridge for instance 0 (including vlan 1, 99). That's perfect
BUT.....on Cisco, the command "show spanning-tree vlan root' shows that the CISCO switch is the root bridge for vlan 99 except vlan 1.
CISCO#show spanning-tree root
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0001 4096 b8af.6763.e67e 4 2 20 15 Gi1/0/39
VLAN0099 8194 0025.8383.3400 0 2 20 15
Neither, the HP switch can become the Root Bridge for vlan 99.
Any idea ??? Should I migrate to PVST on HP ?
Herve
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Another test on HP:
[HP] dis stp vlan 99
Error: Invalid STP Mode
[HP] dis stp vlan1
Error: Invalid STP Mode