Cisco 3702 AP previously joined controller had its IP address changed

[denizyaran]

Hello guys,

Got an interesting question. 

We have two APs that we shipped to an office in middle east. Same APs were in Europe before. 

The controller they had joined previously was migrated to another data centre while the APs were in transit. The controllers now have a different IP address. We have noticed the APs in middle east office are not joining the controllers again. Even we have updated the DHCP option 60 and DNS record. We can see other "new" APs are joining the same controller from the same office.

How can we get those AP joined back again? Why would not join? 

Thank you all.

Serge.

[Leo Laohoo]

So the APs were located in Europe before.  So is it safe for me to presume the APs got a regulatory domain of "-E"? 

The APs were shipped to the Middle East and were configured to join a controller for the Middle East.  So I presume the Middle East WLC has the wrong Regulatory Domain configured? 

If this is the case, then the APs joining the original controller are acting normally.

[denizyaran]

Hi Leo,

Thanks for the reply. The controller is in Frankfurt and uses the same reg domain for all APs.

Other APs in the same office have connected fine. Will it help if we set option 60 on switch DHCP for APs? Controller IP in Hex?

Cheers.

[Leo Laohoo]

Will it help if we set option 60 on switch DHCP for APs? Controller IP in Hex?

Depends on your DHCP server.  We've got InfoBlox as a DHCP server and the IP address is in numeric.  We also got a few routers acting as DHCP servers and they need to be entered in HEX. 

The controller is in Frankfurt and uses the same reg domain for all APs.

The WLC are in FRF and the APs are in the Middle East?  Please know the legal implications for doing this.

APs will always "remember" the last WLC they've joined (unless the APs have been factory defaulted).

[denizyaran]

Thanks Leo.

Yes all APs are in europe domain and then were shipped to Middle East. The reg domain wasnt changed. Does MENA use different channels?

I have replicated this in the lab. The AP was joined to a virtual controller and then I installed another virtual controller. I then added the new IP to DHCP pool on the switch with option 43 and 60. The AP joined the controller which has never joined before.

Does this proof the concept?

Cheers.

[Leo Laohoo · Accepted solution]

Does MENA use different channels?

The Regulatory Domain are different.  The power to some radios are different.  Look at the Data Sheet of the 3700 and it's all stated there.  

I have replicated this in the lab. The AP was joined to a virtual controller and then I installed another virtual controller. I then added the new IP to DHCP pool on the switch with option 43 and 60. The AP joined the controller which has never joined before.

Does this proof the concept?

DHCP Option 43 & 60 has always been the cornerstone for Cisco AP deployment.   Even if you have no DHCP Option 43 &/or 60, you can prime the AP and then send it out and it'll always look for the "mothership", i.  e.  the last WLC it's joined to.