Clients connecting to two out of 6 MR33 are not getting DHCP or DNS

[nethelpmaybe]

We are a small office and the Meraki APs have been working great until yesterday. Clients (Windows laptops, Android and iphones) are able to connect to 3 different SSIDs (2 internal, 1 guest) but the clients on the internal SSIDs are not able to connect to the network. They're getting self assigned IPs. If internal clients roam to those two APs they lose their IPs. 

The 2 internal SSIDs have DHCP relay and Vlan tagging enabled while the guest SSID do not. The guest SSID DHCP is managed by Meraki.

I'm stumped as to why only those two APs are having problems. We did change the domain administrator password recently but I doubt that would cause problems for the APs. 

All APs are on firmware MR 25.13.

[DarrenOC]

Have you checked your DHCP server for stale IP’s? What’s the lease time on your scope?

Have you reviewed the logs on your DHCP server?

[nethelpmaybe]

Yes I have, the DHCP servers have more than enough spare IPs. The lease time is 12 hrs.

[cmr]

@nethelpmaybe have you rebooted those APs?  I'd also upgrade them to 28.1 as you are running a very out of date firmware.  With the newer firmwares you often get better diagnostics and the health feature may well tell you what is going on.

[nethelpmaybe]

@cmr Yes I have rebooted those APs but that didn't resolve the problem. Updating the firmware requires planning with the MSP which will take some time. 

[cmr]

If you look at the dashboard for a client what errors do you see on the history tab when it connects to the APs causing issues:

 

[DarrenOC]

Pretty poor of your MSP to respond so slowly to such a basic request as upgrading firmware!

They don’t even have to upgrade all the APs. Create a new Network and move a single AP over, upgrade and test. Five minute job.

[Bruce]

@nethelpmaybe has anyone changed anything on the switch ports that the APs connect to? It’s almost as if the VLAN that the SSID uses is blocked on the switch ports that those two APs connect to. The guest SSID which uses ‘Meraki DHCP’ NATs to the AP management IP address, which is likely on the native VLAN, which will probably still work if the switch port has been turned into an access port. To me it all points to the switch ports....

[nethelpmaybe]

So my colleague found the problem, the Cisco switch that the two APs were connected to lost the latest configurations that he made a few days ago after a reboot. Re-applying the changes fixed the problem. 

Thank you everyone for suggesting potential fixes!

[DarrenOC]

Everyone always blames the network and I guess in this case that rings true.

glad to hear it’s resolved