we have a topology that we have two cisco core switches 6509 acting as a root bridge running PVST+ and configured in such a way that for add Vlan's one switch is acting as a root bridge and for even Vlan's the other 6509 is acting as a root bridge.
We have some network flip and there was an outage of around 30 min. When we investigated we found that for Vlan A and Vlan B while checking the spanning-tree it shows the designated root <MAC-ADDRESS> is getting learned from one of the HP Pro-curve switch.
This is the same case with both Vlan A & B
That designated MAC-ADDRESS is actually the MAC-ADDRESS of one of the uplink of HP Pro Curve switch.
Now this HP switch is connected in such a way that one uplink on the cisco access-layer switch is configured on Vlan A and one uplink was configured on Vlan B which is connecting to the other cisco access-layer switch.
Please suggest how can i make sure and what changes i will do that for Vlan A and Vlan B my both core 6509 will act as a root bridge which is the best and cisco best practice.
If that HP switch is acting as a root bridge for Vlan A and Vlan B does it also show that ' This switch as a root' like we can see on cisco switches.