CW9166I-A lost ip address periodically after couple of hours

[manish5414]

Hi Experts 

I have a cisco access point CW9166I-A. It was successfully joined with the C9800 controller. However I noticed the access point is losing its ip address after every couple of hours, and ICMP request back with RTO. I had to reboot it every time, and after rebooting, it would join the controller without any issues.
In the logs, i did not find anything suspicious. 

I performed a factory reset, but nothing is helpful,. I have another access point connected to the same switch and that has no issue at all.

Can you please help me to how can i troubleshoot this issue
I appreciate your time and support 

[marce1000]

   - Look into https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/config-guide/b_wl_16_10_cg/enabling-syslog-messages-in-access-points-and-controller-for-syslog-server.html

    The idea is have syslog for both APs (and controller) ; it might give you more insights ;
                                      https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/config-guide/b_wl_16_10_cg/enabling-syslog-messages-in-access-points-and-controller-for-syslog-server.html#config-syslog-server-for-an-ap-profile.
                   Use the above directives for the profile used by the particular AP.

 M.

[Leo Laohoo]

What is the firmware of the controller?

What is the model of the switch the AP is connected to?

[Rich R]

And adding to what Leo said:
- how is the switch port configured?
- packet capture on the switch port to see what happens when the AP should be renewing DHCP.  Presumably the reason it loses IP is because it can't renew so that should be what you're focussing on.  And if DHCP is timing out I'd expect to see that in the AP logs.  And eventually the AP should reload in an attempt to recover.
- what happens if you do a "capwap ap restart" on the AP instead of reload?

Make sure your software is up to date as per the TAC recommended link below.

[manish5414 · Accepted solution]

Thanks Everyone for replying to this thread. I have successfully fixed the issue by changing the AP ip configuration from static to DHCP.
However, I am not clear why having Static ip configuration is having issue? 

[marce1000]

 - @manish5414   Static IP's for AP's are never recommended , because the AP may fallback to DHCP when it can't find a controller
                             or senses a current change in vlan assigned (e.g.)
                             Ref :  https://community.cisco.com/t5/wireless/ap-ip-assignment-static-vs-dynamic/m-p/4975097/highlight/true#M264086

  M.