STP question

[The_guroo_2]

hi we have a new network scenario is as under:

4500 series switch

2 X nexus 5020

3 X IBM blade chassis module

two nexus swicthes are conected to 3 X IBM blade chassis module (each nexus has 3 links network module  of balde chassis via 10G fibre) each blade chassis has two network module (both active)all links are trunk links

both nexus are connected to each other as well.

both nexus are conected to 4500 switch (trunk ports) all the vlan interfaces are on 4500 (nexus is layer 2)

The scenario is fully reduandnt for any failure PVST is running. Now the question is which links will be blocked by STP.... if i want to make one nexus to carry all traffic (first one) what i have to do.

Thanks

[Amit Singh]

The easiset one for you would be to configure Nexus5K 1 as the primary root bridge and Nexus5K 2 as the secondary root bridge for the vlans, use Cat4500 just a L3 router for routing. This way you all the uplinks and downlinks from the N5K 1's perpective will be forwrading.

If you want Cat4500 with the Vlan SVI for routing to be your root bridge for this topology, then you have to play with the root path cost. You have manually increase the path link cost on Nexus5K2 for uplink and downlink ports.

HTH,

-amit singh