WAP ports being disabled by STP on Meraki switch?

Building a reputation

WAP ports being disabled by STP on Meraki switch?

Hey Meraki Community,


Two different customers over last week reporting WIFI issues. We check the WAP and Meraki, devices are not showing they have any issues. We then check the switch ports which the Meraki is connected to and find it flopping on and off. Event logs show STP change.


Both clients have MS120 switches, but client one uses MR33 and client two MR46. All devices have been rebooted and firmware up to date. Any else having this issue? Find it strange this just started happening.


Meraki wants us to go factory reset all devices and if it still keeps happening they will RMA. What a PITA.







Kind of a big deal

I can't help with the issue, but just as a note the STP change is a consequence of the port flap, not the other way around. You see the port go from 1Gbps Full Duplex to down, and STP responds by moving the port from designated to disabled. If you can fix the port flap the STP change will likely go away.


What is causing the flap is just a case of eliminating the variables. Check the cables, reboot the WAP, if you've got a spare port on the switch try that, and if all that fails, as Meraki support said, reset the WAP.


Did anything change when this started happening? MS firmware upgrade, MR firmware upgrade? Adding a new MR to the switch? (maybe taking it over the PoE budget).

Building a reputation

Cables are all good, this is a brand new switch but we do have a second we can try. I find it strange only the WAP ports are flopping. Meraki does not log in the change log on dashboard when firmware upgrades were completed, so not 100% sure if firmware changed from auto-update but I cannot find an email.


Issue is still happening, we are on hold with Meraki now but very frustrating. No way four cables are bad + cable at another customer location all at once. This feels like bad firmware.


Meraki does show new firmware upgrades fix an issue with MS390 doing port flapping, but we have MS120.

Head in the Cloud

I connected the MR´s with trunk (to get different WLAN´s into different VLAN´s). But I did an allowed VLAN at the trunk ports to avoid spanning-tree issues. I allowed only the necessary VLANs on the ports with MR´s and I switched on "BPDU-guard" because in fact it´s an edge port.


We have different networks with MR42, MR44, MR45, MR46, MR52, MR84 and so on. Switches are MS120, MS220 and MS225.

Running firmware is MR28.4 for the accesspoints and MS14.24  up to MS14.29 for the switches.



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