I was reading this post from a couple of years ago:
https://supportforums.cisco.com/document/11935956/vpc-peer-switch-deployment-options
I've been reading this in conjunction with vpc best practices
http://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf (Novenber 2015), the following section has got me thinking whether I should be using peer-switch (same SPT VLAN priorites) over not using peer-switch and having a primary and secondary root bridge configured on the N7K aggregation layer.
Section vPC and Spanning Tree Protocol Bridge Protocol Data Units
Strong Recommendations:
● Always define the vPC domain as STP root for all VLAN in that domain (configure aggregation vPC peer devices as STP root primary and STP root secondary)
General Recommendations:
● Configure the Spanning Tree Protocol root for all VLAN on vPC primary device (spanning-tree vlan 100-102 root primary)
● Configure the Spanning Tree Protocol secondary root for all VLAN on vPC secondary device (spanning-tree vlan 100-102 root secondary
therefore Im still a bit unsure as to whether we should be configuring peer-switch as default best practice (and matching SPT vlan priorities) no matter whether we use a pure vpc or hybrid environment.
I think the answer is going to be yes but would like clarification on my understanding if possible to the following:
- in pure vpc environment like 2.1 topology peer-switch should be configured , this will allow for faster convergence of the STP topology when a failed N7K is restored, rather than configuring SPT root and secondary priorities on the N7K aggregation devices.
- peer-switch is only configured on the N7K aggregation layer and SPT vlan priorities MUST match on both the primary and secondary N7Ks.
- There is NO need to configure peer-switch on the access layer N5K's.
- In topology 2.1 , is there any need to configure STP vlan priorities on the N5Ks or leave these to work themselves out.
Thanks in advance.
regards,
Dave.
