I'm helping a client, and almost all the APs are flagged with a 100% connection failure. The event log for the AP reads:
(WARNING) AP NAME flagged health  because it crossed the threshold .
(INFORMATIONAL) AP NAME flagged health  because it crossed the threshold .
I can find nothing that would be causing this. Clients also don't seem to be having trouble using the network, though WiFi Calling seems to struggle with dropped calls. (not sure if related).
We made sure that there is no co-channel interference (Smaller channel size, set a static plan, and ended up disabling background scanning (some people said this could effect VoWiFi calling).
Any input or recommendations would be greatly appreciated. I could find very little on the topic except for posts saying that under 3.6 connection failures were being falsely reported. This however, is occurring on 5.0.
Below is a graph of what we are seeing. The same behavior is seen on the 5 Ghz. APs are all 610s, with one 710.
I think there is a switch for "log historical connection failures" which may help. otherwise, just because I don't know a better way, I use the packet capture dialog on the AP with the high failure rate. This will give me the disassociation code while i review the captures in Wireshark, and allow me to see which STA has either a bad password or has some other type of issue ( I'm looking at you Surface Pros).
wow, so when I see dhcp issues, i immediately look for my Wireshark to confirm. in my case, this is almost always either a Trunk DHCP trust issue, DHCP helper issue, or a Vlan traversal issue. sometimes by using pcap on the dhcp server, i can see "Oh my requests are coming in from the wrong vlan gateway." which I've seen in networks with a collection of a different manufacturer or versions of switches. (3560, 3750 cisco, 12.2 IOS to 15.x IOS).