Right here goes...
At site A we have 1 WCS server and 3 WLC 4404's
At site B we have 2 WLC 4404's
At site C we have 3 WLC 4404's
Site A and B are fine but site C has a problem where clients will lose connectivity after approx 90 days, and then fail to re-connect.
They will connnect to the WLAN but not get a DHCP address, and get put in the excluded list.
The config looks almost the same on all 4404's and the version is the same.
Of the 3 WLCs at site C I get "control and data path down" between 2 of them. If I mping and eping them they will return to an "up" status but then back down after 30-60secs
Here's the odd bit - I have a laptop and travel between all the sites and never had a problem at site C. I took one of the failing PCs from site C to site A yesterday and it connected fine.
I brought it back today and it suddenly worked again! It's like it needs to roam to keep it "alive"
DHCP lease time is set to 8 days.
I've rebooted the WCS and all 3 WLCs on site C with no difference.