I have an installation with 17 Cisco AIR-LAP1242AG's connected to a pair of AIR-WLC4402-25's. The system was running a 5.1.x.x code release and has been for over 6 months, well I decided to upgrade to the new 18.104.22.168 code which seemed to go flawlessly except for two access points. Now before I get into the issue and the resolution, I must state that all of the AP were LWAPP right out of the box and went thru several progressions of the 4.x.x.x code and have never been meshed.
So the issue was that 2 of the AP's failed to come back to the controller, I checked them and found the error lights indicated they were searching for a controller.
Here are the troubleshooting steps I went thru:
Reset the AP
Reset the AP with the mode button
Converted it to IOS and reconverted to LWAPP ( It joined, upgraded code then dropped off and never came back)
Converted it to IOS and reconverted to LWAPP a second time ( It joined, upgraded code then dropped off and never came back)
At this point I watched the boot process and noticed something about a file called mash.cfg and I converted the unit back to IOS.
From here I looked at the flash and saw there were 3 files: meshcfg.???, mesh_cfg.???, and mesh.cfg... Oddly both AP's that were behaving oddly had these files. I did another mode button reset both config and firmware recovery (and used a TFTP to reload the IOS image again) and the files were still there.
I deleted these three files and then re-converted the AP's and they are working fine; I converted one of the AP's that didn't experience the issue and checked it's flash and those files were not present.
Question: So has anyone else had this experience when converting from 5.1.x.x to 7.0.98.x with the Cisco 1242's? Hopefully if so this will save you some headache.