Pair of Cisco 9k as Primary and Secondary Root

[Barry Landon]

We have two Cisco 9k running as our cores.  They run as a pair, if one goes down the other takes over.  We have around 20 vlans all seeing as Cisco 9K SW1 as root.  Can i add secondary root command to Cisco 9K SW2 baring in mind they are both seen as one whole switch. The root primary commands only appears on Cisco 9K SW1.

[balaji.bandi]

Cisco 9K ( is this catalyst 9K - what model ?) or Nexus 9K ?

is this stacked or stackwise virtual ?  root in terms of Spanning treed ?

you can add higher value than in the Primary so other switch become secondary of the primary go down.

example :

Primary vlan priority 4K

Secondary  vlan priority 8K

[Barry Landon]

Thanks for the quick response.  The switches a stackwise virtual.  We have mirrored vpcs running on each. OK so from what your saying i can add the Cisco 9K sw2 as secondary root.

[balaji.bandi]

You still not confirmed the Model of the Devices ?

The switches a stackwise virtual.  - If this stack wise virtual  ( Physically 2, but logically 1 only ) - You do not need to configure spanning tree seconday (not you get option to change anything on the passive device)

We have mirrored vpcs running on each.

this confusiing to me ( is this nexus ?)

[Barry Landon]

The deice is a Nexus C93180YC-EX.  The device is stacked and not stackwise virtual.

[balaji.bandi]

 Nexus C93180YC-EX.

Nexus work in different way (nor it stacked or SWV)  - they work as vPC in teh domain

You can make priorties as suggested for spanning tree ( if required) - most case you do not need.)

[paul driver]

Hello

if they are logically stacked - vss-vpc-stackwise then the stp root priority should be the same

What stp mode are you running?