We have the 5508 controller(software: 184.108.40.206) with over 45 3702I & 1142N APs around campus. The whole wifi network seemed to be working fine for quite a few years until the past one or two years with adding more APs on the network. We used to have only 25 1142N APs a couple of years ago and for the past 3 or 4 years we replaced most of the APs with 3702I and adding more APs and now there are more than 45 APs mixed with 3702 and 1142 around campus. I realized that for the past one or two years, random APs got disconnected from the network. They are not totally off the network but look more like stuck because I can see them from the controller but no client connected to them. Resetting the APs does not really help and I have to physically unplug the ethernet cable and plug it back. And even with this way I still need to wait for a long time before they can actually join the network and see clients connected to them. The time to wait for them to get back online is mostly a couple of hours or about 5-10 minutes for one or two of them.
Any idea what might went wrong? Thanks much in advance!
What WLC software version are you running.
is this happening to both the 1142s and the 3702s or just one model?
The 1142s are EOL and i have seen funny things happening with them.
I have also seen bugs where only an over the air packet capture will really see it, where the AP is broadcasting the SSID but not accepting the association.
Have you done a debug client and seen if they are actually trying to associate to that AP?
Since you got 1142s, you have to stay with 8.3.x release. Go with 220.127.116.11 & upgrade your WLC software, Hope that will make it stable
Here is the software compatibility information that you should book marked.