We have two APs in a remote area that are connected back to core switch via l2vpn. We have created a special ap system profile to use a lower MTU. This worked fine until we upgraded the code to 6.3.1.5. Now APs are unable to join.
A factory reset will allow them to join, but if connectivity is lost for any reason, they go to reboot cycle.
I can see via the datapath session table that there is connectivity. I spanned a port connected to one of the APs and can see it sending packets to the wlc on port 8211, but nothing coming back from the wlc.
Previous SAP MTU was configured for 1450, I have since lowered it to 1100 but still no luck.
Any ideas?