Cisco Aironet – AP disconnects clients and disappears

ciscowifi

I have a Cisco 881w with an AP.

Sometimes, the wifi just drops its clients and the wifi network disappears. The wired network is still working fine.

Also the wifi network reappears after a couple of minutes.

How can I troubleshoot this issue please?

Best Answer

I would start with looking at the router logs by using show log.

Like any cisco, if logging is enabled, you should see at least some %DOT11 messages like %DOT11-6-ASSOC, %DOT11-6-DISASSOC...

To enable logging with a 10kB buffer (default is 4096bytes):

router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
router(config)#logging buffered 10000

If nothing obvious appears from the logs, you could try to activate some debugs on the router:

router#debug dot11 ?
  Content-Engine     cisco content engine service module
  Dot11Radio         IEEE 802.11 WLAN
  Service-Engine     cisco application engine service module
  aaa                Authentication, Authorization, and Accounting
  arp-cache          ARP Cache
  events             IEEE 802.11 events
  forwarding         802.11 AP forwarding
  mgmt               802.11 Management
  network-map        Network Map
  packets            IEEE 802.11 packets
  syslog             Turn Off Dot11 syslog msgs
  virtual-interface  802.11 virtual interface

That should help to troubleshoot the issue.

Be sure also to disable logging console as logging on the serial console generates a cpu interrupt for any character (hence a high cpu usage), and prefer terminal monitor if you're debugging from a vty (telnet/ssh).

A syslog server would be quite useful also. It will store all the logs from the router, and they can then be processed (script of some kind, your eyes...) on the server.

router(config)#logging ?
  Hostname or A.B.C.D  IP address of the logging host

router(config)#logging <ip of syslog server>
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