Please help me with this question.
I'm doing a data center design that will have 2 5548 Nexus uplinked to 2 6509 1 interface to each. The 6509's are not running VSS. How do I configure spanning tree so that both Nexus don't use one 6509 as root and block on the other? I want One Nexus to forward on Core1 and block on Cor2, and the other to Forward on Core2 and block on Core1. All the servers connecting to the Nexus switches are in 1 vlan.
Thanks in advance for your assistance.
Is this an single VLAN scenario? If so, there is no way to do what you are asking. There can only ever be one root for any given VLAN.
If you are going to use multiple VLANs that is a different story. You could use PVST or MST to root half the VLANs on one 6500 and half on the other.