Hello everyone. My apologies if this ends up being a duplicate post - my first post disappeared for some reason.
I'm having an interesting issue with a variable number of AP's failing the "Layer 3 Roaming Test" on our primary SSID. We just deployed a full Meraki network (MX, MS425, MS250, MR30H, MR46) to our university's Residence Hall network. We have about ~675 AP's deployed, and, the SSID in question is configured for Layer 3 Roaming. We have a VLAN per room, setup with VLAN tagging, so students get a "home" VLAN when they connect their devices in their rooms.
In any event, when we run the Layer 3 Roaming test, a random number of AP's, between 12-34, are "unreachable". If you run the test 5 times in a row, you can get five different numbers of AP's that are unreachable. It's the same ones over and over, but sometimes they get removed from the list, and sometimes re-added. If you check each individual AP in the dashboard that is "unreachable", they are online, fully functional, and have no issues. Nothing of interest in the event log. The APs are already on switches that have AP's connected that are reachable on the Layer 3 Roaming test at all times. So far for troubleshooting, we've restarted AP's, re-tagged the AP's, re-configured switch ports they are connected to, and deleted and re-added the interfaces they are using in the dashboard. So far none of those steps has resolved the issue.
We've opened a TAC case, but was hoping for some feedback on how to proceed on my own as well. This one has me really stumped, and I've tried to do some research on "Layer 3 Roaming Test" failures and haven't found much. I'm open to any suggestions - and let me know if I need to provide any other information that might help the community better understand this problem.