STP Issues

JustinGA
Getting noticed

STP Issues

Hi everyone, hoping for some help, guidance.

 

I have a mix network of catalyst 2960s and MS250 / 120 switches.

 

My MS250s that are plugged into 9372 Core 1 always have a High Rate of STP topology changes on port XX..

 

When I plug them into 9372 Core 2 they don't.

 

Core 1 is my root bridge.

 

I'm not sure how to tackle this as it doesnt seem to be harming anything, but I dont have it in me to stop trying to fix it.

 

I have attached a bad depiction of my network in below:

 

network layout.jpg

 

 

7 Replies 7
alemabrahao
Kind of a big deal
Kind of a big deal

Have you tried using MSTP on Catalyst switches and 9300?

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
JustinGA
Getting noticed

no, too be honest.. im not familiar with that or how it would be configured.

JustinGA
Getting noticed

@alemabrahao have you experienced this kind of thing before? I took over this from over 10 years of other people blindly setting things up, and I'm just trying to get it all solid.

 

I appreciate the help!

 

PhilipDAth
Kind of a big deal
Kind of a big deal

As @alemabrahao says, enabled MSTP on all your Cisco Enterprise switches.
spanning-tree mode mst

 

Is there anything interesting in the logs on your 9300s?

cmr
Kind of a big deal
Kind of a big deal

Have you tried setting them to different values, not all set at 32768?  i.e. one at 12k, one at 16k etc.

JustinGA
Getting noticed

I had read that as a possible solution... Would it be fine to change all the MS to that? 

JustinGA
Getting noticed

I think i have been able to determine using packet capture that the TCNs are happening on the VPC between the 2 9372s.

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