RSTP Help

[rayelkin]

Hey community members:

Looking a bit of help here.  I've got to migrate from an older Cat 6509 pair as core switching over to a pair of Nexus 7k switches as core.  The ask is to perform the migration with as little downtime as possible; <60 seconds. When bringing up the vPC links between the 4510 to Nexus 7K the port roles I get are 4510 <designated> and Nexus 7k <alternate>.  Looking for a way to manipulate RSTP to change the port roles to 4510 <alternate> and Nexus 7K <designated>. 

[Fraydoon Razazi · Accepted solution]

Lower the spanning-tree priority on both 7K to lower than 4510.

spanning-tree vlan 1-4094 priority 4096 !(Must be lower than 4510)

or

spanning-tree vlan 1-4096 root primary

[rayelkin]

Thanks!  We will give that a shot.