Uplink port always display orange status with STP high rate topology changes

[cuiL]

Those port have configured LACP cross stack aggregation from ACW(MS120) to DSW(MS390), all switch running 15.17 firmware. Any advice how to narrow down the issue to figure it out?

[alemabrahao]

You must set the highest priority for the core switch to prevent disputes over who will be the root of the topology.

https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Configuring_Spanning_Tree_on_Meraki_...)

https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Spanning_Tree_Protocol_(STP)_Overvie...

It's a good idea to review the concepts of STP.

[cuiL]

Hi Alemabrahao,

Thanks for more info, however, i has been check each access switch have the rstp root via core switch with priority 4096 which is correct path. not sure why still getting stp high rate, or i have to adjust priority to 0? even those root switch is already core switch. I also review the physical cable that might be suspected connection loop and I'm sure now that our network is loop free but still getting those alerts and sometimes no alert.

[alemabrahao]

This is looking like a network loop, maybe it's better to review the LACP settings.

[alemabrahao]

And always It's a good idea t set the highest priority (0) on the root switch.

[GIdenJoe]

RSTP topology changes are generated when a non edge port comes up.

If you are using the default trunk native vlan 1 configuration for all your access ports you could be generating a load of TCN's.

Please configure all ports that go to endpoints as access ports.  Meraki software enables edge port / portfast automatically on access ports.  Edge ports do not generate TCN's when they come up.

If this is not the case then there must be a part of the L2 domain in your network that actually does have unstable STP topology.  Make sure you really check out the entire network.