Migration issue of 2702i and 2802i to WLC 9800

[FreddyJay]

Hi all!

I am trying to migrate my AIR-CAP2702I-E-K9 and AIR-CAP2802I-E-K9 (nearly 200 APs) to my new WLC Catalyst 9800-L-F-K9, DHCP Option 43 is enabled and correctly set, DNS is correctly set. However when I try to send them to  the new WLC (9800) they rejoin to their current WLC Cisco 5520. 
What I do to mitigate as a workaround is to change High Availability parameters towards the new WLC and restart the AP. It will then end-up in the new WLC. Since it is not a sustainable solution would you have any suggestion?

Thanks.

[balaji.bandi]

Option 43 only kickin for new AP, the one joined already always join with same WLC as per i know.

so reset the AP and test it.

[FreddyJay]

Thank for the reply. This scenario happens when I have restarted an access point in order to send them.

[balaji.bandi]

is this means new AP ? can you explain more

[ammahend]

If you have prime you can push the new controller IP using a template, if not try creating an ACL on AP Vlan svi and block 5520 management IP permit everything else.

[Arshad Safrulla]

Cisco recommends multiple options,

1. Configure the primary wlc on all AP's under the AP >> High Availability manually or you can configure it from the AP CLI, command is "capwap ap primary-base  <NAME> <WMI IP>. If you want to do it via WLC CLI then use "show ap summary" to get the list of AP names and then use the command "config ap primary-base <New 9800 WLC name> <AP NAME> <WMI IP>"

2. Use a different management VLAN for AP's and during the time of migration just re-configure the switchports to the new VLAN. You can configure option 43 under this VLAN's DHCP option pointing to the 9800 WMI.

3. Use Cisco PRIME template to move the AP's.

Once the AP's are moved please make sure that the tags are saved to the AP's. You can use the below script if you are in 17.3.x 

https://github.com/fsedano/eem_ap_push

if you are in 17.6.X codes you can do it via WLC itself.

[Leo Laohoo]

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@FreddyJay wrote:

However when I try to send them to  the new WLC (9800) they rejoin to their current WLC Cisco 5520. 

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What method was used to send the APs, from the 5520, to the new 9800?

[Rich R]

The answer is already above from @balaji.bandi  - AP will always prefer last WLC.  Simply restarting the AP will not make any difference.

Factory reset / default config / erase config will allow it to discover new WLC but behaviour can still be unpredictable.  The other options are already mentioned above too.  If you want to be sure they only join the 9800 then move them to a new VLAN which can only reach the new WLC.