Cisco 5508 WLC AP Issue

[pbxnkey]

I have (2) 5508 WLC's. One has about 145 AP's and the other about 160 AP's.
Initially the AP connects to the first controller using DNS. Afterwards I configure it to connect to the 2nd controller bu configuring the Primary Controller in the settings.
The controller names are: WLC1,WLC2
I inherited this setup and was told to configure the AP with a Primary controller name of WLC1.controller.com or WLC2.controller.com
We have been doing this for over a year for both controllers. Lately when I configure a new AP with a Primary Controller name of WLC2.controller.com and I reboot the AP it connects with WLC1 instead of 2.
I opened a TAC case and was told that the name of the Primary Controller was configured incorrectly. It should not have .controller.com, so we removed it and it moved over to controller 2.
i just don't understand why for over a year this has been working and now all of a sudden I have to change the name.
Does anyone have any ideas?

 

[Viconsul]

Hi,

Do you own the domain name "controller.com"? if not that may be your problem, because that domain name is registered and valid, so if your dns server is queried for wlc2.controller.com, the request is forwarded to the authoritative name server for that domain which will then answer appropriately.
You can overcome this problem by setting up a split dns server in your network and simply create records for wlc1.controller.com and wlc2.controller.com which point to your internal network rather than query the authoritative dns server for the controller.com domain.

HTH
-Viconsul

 

[pbxnkey]

The controller.com is something I used no this post to explain my issue. The customer does however have a domain controller and a dns server. There is a dns entry for CISCO-CAPWAP-CONTROLLER that resolves to the WLC1. I confirmed this by pinging from within the customer's network.
There is not however a dns entry for WLC1.controller.com or WLC2.controller.com.
That's why I don't understand why this has been working for the past year and now I have to remove .controller.com when I configure new AP's to WLC2.
Just want to add that the AP's are on the other end of an MPLS circuit. They are configured for HREAP.
Thanks for the input.

 

[baddos]

It's entirely possible someone deleted the dns records for the two controllers or they becamse stale and dns cleared them out.