after black out how to let APs automatically join the controller

[haedongchan]

before black out there were 66APs on cisco 5500 Controller

but after black out there is no APs on controller

I expected that AP would automatically join the controller again

but my expectation was wrong.

pls help me guys

[Leo Laohoo]

Check the time and date of the WLC.  If they are wrong, the APs will not join. 

Check if the APs get valid IP address. 

[haedongchan]

Thanks for the help

total APs were 66, but 64APs joined controller automatically, but 2 APs did not join the controller

I can see the mac addresses of two APs on switches, it looks fine

how can I rejoin the these two APs

[Leo Laohoo]

Are those two APs getting a valid IP address?

[marce1000]

 - Which mechanism(s) do you use for AP's to have them discover a controller , are they still in place and working ?

 M.

[Kasun Bandara]

Hi,

you dont need to do anything if WLC's time and time zone is correct after reboot. APs will get IPs from previous DHCP servers and will join. check time and time zone of WLC.

rate this and mark as answer, if this solved your issue

[haedongchan]

Thanks for the help

total APs were 66, but 64APs joined controller automatically, but 2 APs did not join the controller

I can see the mac addresses of two APs on switches, it looks fine

how can I rejoin the these two APs

[patoberli]

Did the APs also have a power outage? Can you attach a console cable and post the full boot up log?

[Rich R]

Also check https://www.cisco.com/c/en/us/support/docs/field-notices/639/fn63942.html