High rate of stp topology changes on aggr ports connected to Alcatel

Mang
Comes here often

High rate of stp topology changes on aggr ports connected to Alcatel

Hi everyone.  Last summer we deployed 10 MS125s, one to each IDF in the building.   Each MS125 has two fiber connections back to a stack of two Alcatel fiber switches, one fiber to each side of the stack for redundancy.  Both the Meraki and Alcatel side of these aggregate links are configured LACP.  Our network also has a number of older Cisco switches with separate single fiber connections back to the Alcatel fiber stack (although this is probably not relevant, just fyi)

 

While traffic seems to be flowing just fine, each one of the MS125s has been reporting "high rate of stp topology changes" since the very first day of deployment.  Our Alcatel service provider confirms that the link aggs are all configured correctly.  The Alcatel fiber stack log does not indicate a high number of stp topology changes.

 

I've noticed that each aggr link (51,52) on each Meraki reports different LDP/CCP info. 

 

51 shows just just the link back to the Alcatel fiber stack (which is what I would expect):

Mang_0-1646156604785.png

Port 52 shows a list of every switch on the entire network (which seems odd):

 

Mang_1-1646156775976.png

 

As I mentioned, traffic seems to be flowing just fine, but I'd thought there might be a solution to the reported stp topology changes (are they even really happening?  Also, I believe this is why the Meraki topology map is different and incorrect every time I check it.  It shows switches connected to other switches that are not connected that way.  Indeed, we have a fairly straight forward star shaped network

 

Any thoughts?

 

 

2 Replies 2
ww
Kind of a big deal
Kind of a big deal

Are your trunks all native vlan 1 allow all?

Is your alcatel  the root switch?

What stp protocol runs on your cisco-ws and alcatel?

Mang
Comes here often

Yes, trunks allow all

 

So I have another stack of 8 Alcatel switches in the MDF that is connected to the fiber stack.  It is the root, not the fiber switch stack

 

Alcatel are RSTP

Ciscos are pvst+

 

 

 

 

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