First thing to check with all vWLC cases

[Jeffrey Keown]

First thing to check with all vWLC cases

Connectivity problems of any sort: radius timeouts, client ip connectivity, ap's unstable

check vWLC's message log.  if you see this:

#LOG-3-Q_IND: dhcp_proxy.c:3754 Received a DHCP packet sent by the controller itself possible network loop![...It occurred 5 times.!]

With a very high degree of certainty, the issue documented in this bug is the cause:

 CSCuj14843     vWLC: prevent service/data port confusion

To fix:

via the vWLC's vm, create a new vswitch that is not mapped to a physical nic.

map the service port to it

save the vWLC's config and power cycle the vm

[gohussai]

Well said ,adding to this try using Firmware >=8.0 instead  7.5 as it has few crash problem with 11xx series AP.