%SPANTREE-5-ROOTCHANGE Root Changed for vlan 123

[ioannisv]

Recently we have added a switch as secondary root bridge and we are getting :

013296: Jan 6 2022 20:05:38.128 Cyprus: %SPANTREE-5-TOPOTRAP: Topology Change Trap for vlan ZZZ
013297: Jan 6 2022 20:05:38.128 Cyprus: %SPANTREE-5-ROOTCHANGE: Root Changed for vlan 113: New Root Port is GigabitEthernet1/0/24. New Root Mac Address is xxxx.xxxx.xxxx

There is no evidence of link up/down or error on connectivity with the uplink between switches.

What could be causing the above behavior?

[balaji.bandi]

if you do not set up the spanning-tree root priority spanning root election kicks in

as explained below :

https://www.certificationkits.com/cisco-certification/ccna-articles/cisco-ccna-switching/cisco-ccna-spanning-tree-protocolroot-bridge-rootdesignatedblocked-ports/

Recently we have added a switch as secondary root bridge and we are getting :

explain more will helpfull here.

[ioannisv]

The designated switch is configured with priority "4096" and the secondary with "24576"

As for the logs received every minute or so (on the secondary) :

026228: Jan 7 2022 07:43:19.938 Cyprus: %SPANTREE-5-ROOTCHANGE: Root Changed for vlan 64: New Root Port is GigabitEthernet1/0/24. New Root Mac Address is xxxx.xxxx.xxxx
026229: Jan 7 2022 07:43:43.965 Cyprus: %SPANTREE-5-TOPOTRAP: Topology Change Trap for vlan 31

[balaji.bandi]

to come to understand we need your network topo and full config to understand, along with show spanning tree information

[paul driver]

Hello
GigabitEthernet1/0/24 has become the root port due to a stp topology change being initiated in the switching estate, if you have made any changes, adding additional trunk ports or new switches this could be the reason.

[ioannisv]

unfortunately none of the above occurred and that's worries me a lot.

Since the link between the root and the secondary is not direct , that could be causing the issue?

[Georg Pauwen]

Hello,

I remotely remember a similar case, the solution was to delete and then re-add the Vlan altogether. Which obviously can cause a disruption to your connectivity, so you might want to do this after hours.

[paul driver]

Hello
So you have had no link/port failures, added/removed no switch's/trunks etc. Manually pruned any vlans off trunks, create vlans that trunks are been pruned from?
Are you running vtp and if so are all your switches running the same version ?

[ioannisv]

Vlan delete and create did not help.

As for the VTP version , all switches are on the same v2 with pruning enabled.

How do i manually enforce vtp pruning?