Switch Stacking

[myndwire]

Hey folks,

I just want to make sure this is a viable configuration, because I've been fighting some awful strange issues that I cannot explain, and Meraki support hasn't been an enormous help.

Scenario:

MS225-48FP access stack of 4 switches, configured in the typical ring fashion. LACP from switch 1 and 4 (2 links) to a single MS425-16 (core). MS425 is the sole device as STP root (priority 0). 

I am then doing root guard on core to access links, and loop guard on the other side, as well as loop guard on AP ports all across the access stack. I would imagine if there were any major problem with this setup, Meraki would complain somehow.

MS425-16 merely uplinks into my MX250. Every link in the scenario is a trunk.

[Ryan_Miles · Accepted solution]

I'd put BDPU guard on the access ports and root guard on the switch to switch links and leave it at that. 

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

[myndwire]

Root guard on the access switch side, core switch side, or both? I'd imagine just at the core.

[Ryan_Miles]

Per the doc 

"It is recommended that Root Guard be applied to ports connecting to neighboring, downstream switches that should not be the Root Bridge, to prevent a superior BPDU from being received on the port and causing the election of an unexpected Root Bridge."