R650 APs showing 'disconnected' in ZD1200 & need reboot from CLI to solve until next time

[jmas]

I have a site with R650 APs still on a ZoneDirector 1200 running 10.5.1.0 Build 199 that all eventually show up as 'disconnected' in the ZD after an undetermined period of time.

The APs and ZD are in the same vlan and IP subnet and the only changes recently were the addition of the R650 APs (previously R500). In this state the APs still broadcast SSIDs but won't get any config changes from the ZD, they are still on the network, reachable, and they can ping the ZD and the ZD can ping them. From the AP-CLI 'get director' shows the correct IP & MAC Address.

So far my solution is SSHing into the APs and rebooting. Anything I can check or try to resolve this long-term?

[sanjay_kumar]

Hi @jmas 
There are some things which you can check.
1. Check if this is happening at random times or specific time. You can start by selecting few APs and check their history.
2. Login to the AP and see the Ping latency, and see if there is any drops.
3. Check the MTU size on the ZD config and the Switch (Between the AP and Controller). Make sure the MTU on the switch is higher than the MTU set on the ZD.

If you still have any issues post checking the above parameters, then you can open a support case so that we can check.

[jmas]

Thanks @sanjay_kumar 
1. Unfortunately there is very little to see in the ZD logs beyond a very occasional "Configuration update request failed". I don't even see the usual 'heartbeat lost' type entries that I would expect. The logs go back a full year so I'm not sure why there isn't more data there. Is there anywhere else I could check?

2. Pings to and from any AP that I've tested so far have been low latency, no packet loss, and consistent jitter. This network is very basic in configuration & topology, and not much traffic on it.

3. I'm familiar with adjusting the tunnel-mtu but I can't seem to locate any MTU settings for the ZD's eth ports, and web searches are coming up empty - any tips? Either way, the switch that is between the APs and ZD is configured for Jumbo Frame which is much larger than the ZD's default 1500 - let me know if that's sufficient or how else to check the ZD side.

I just noticed something interesting: I rebooted everything yesterday including the ZD, but the APs all show up in the ZD as having a 366 day uptime - these APs haven't even been installed here that long.

[sanjay_kumar]

Hi @jmas 
It would be best to open a support case so that we can check more on this.

[jmas]

Thanks, unfortunately I came to the forums because the system is out of support right now.