Cisco WLC 5520

[RS19]

Hi All

I have Cisco WLC 5520. 

WLC1 is in Primary Primary DC

WLC2 is Secondary Backup DC

All the APs were registere with WLC1 which is the primary.

Due to communication between loss between the APs & WLC1, all APs switched over to WLC2 which is in the backup DC.
Now I want all the APs to point back to WLC1. 

What is the best way to achieve this ?

[MHM Cisco World]

Controller->general->ap fallback 

Are this feature enable or disable?

MHM

[RS19]

it is disabled

[MHM Cisco World]

https://community.cisco.com/t5/wireless/wlc-manual-ap-failback/td-p/1256983

Then friend check this post'

Hope it call help you to solve issue without rebooting wlc/ap

Good luck

MHM

[RS19]

Thanks. I checked the link. 

I have 300 APs.
As per the link under  Controller->general->ap fallback , I need to change from Disabled -> Enable.
Check all APs are moved & then change back to disabled.
Is my understanding right ?

[RS19]

Sorry can you please confirm if the above is right. I need to do this in anotehr 1 hr. So want to ensrue it is right cause this is productone environment.

[MHM Cisco World]

Ap fallback must enable to make AP back to association with primary.

For your case now what option you have other than ap fallback features?

By defualt this feature enable but I dont why you disable it?

It rare case this feature disable in WLC mobility group.

MHM

[RS19]

Got it. Sorry more details would like to share which I got now from my team.

The purpose it is kept in disabled state is because our team want that all APs should be connected to secondary WLC which is WLC2. 
So at present all APs are registered to secondary WLC2 as per the current requirement.

There is some maintenace tonight, in which again all APs may loose connectivity to WLC2 & the APs will get registered with Primary WLC1.

But after the maintenace my team wants all APs to point back to WLC2 which is the secondary.
How will I be able to achieve this ?

[MHM Cisco World]

AP to WLC1 primary using AP fallback 
AP to WLC2 backup need WLC1 down or reboot and this Op. not enable.

read more about this feature maybe I missing something important to You 

I will share some cisco doc. about this feature help you to select correct op.

big good luck in your task 

MHM

[MHM Cisco World]

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-mobile/71963-apload-apfall-uwn.html

https://mrncciew.com/2013/04/07/ap-failover/

MHM

[RS19]

Thank I got it.
Regarding below point. I understood about WLC1 down or reboot. Didnt understand "and this Op. not enable"
Pls help in clarifying 

AP to WLC2 backup need WLC1 down or reboot and this Op. not enable.

[Rich R]

1. You set primary and secondary on the APs using the WLC HA settings:
2. You enable AP fallback so that APs can automatically revert to their primary.  Note it sometimes doesn't work automatically so the AP may need a CAPWAP reset or reboot to force it back to primary.
3.  Why disable fallback when you can just change the primary and secondary WLC setting?

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-10/config-guide/b_cg810/ap_connectivity_to_cisco_wlc.html#backup-controllers

[Scott Fella]

Like what the others have mentioned, you can achieve fallback with both methods.  However, after you got information on what your team wants, that helps understand what you need to do and what you need to understand.  Like what @Rich R mentioned, setting the high availability on the ap(s) is the best way to tell the ap which is the primary controller, secondary controller and tertiary controller.  

Since you have a lot of access points, your best way to configure HA is by using the CLI.  I have attached a spreadsheet that I create a while ago to be able to move ap's to different controllers especially when I do maintenace.

• On the show ap summary tab, you really just need to copy from the cli and paste as value.  Make sure you issue "config paging disable" on the cli.  You can just put your ap hostnames, but make sure it matches, case sensitive, the ap hostname.
• If you decide to copy and paste as value on the "show ap summary" tab, you need to highlight A2 all the way to the end, click on the "Data" tab on the excel ribbon and find "text to column".  When you click on "text to column, your delimiter is a space.
• This will populate the table.
• The "ap high availability" tab is then used as long as you have not entered any HA configuration on the AP.
• Enter the controller hostname and ip address, remember the hostname is case sensitive. Once you enter these values, then the commands will be shown and generated for you.
• You want to define the primary first, then secondary, then tertiary.  This way with un-configured HA, the ap will move to the controller you want.  Be careful as you might want to take a downtime if the ap's will move.  
• The middle worksheet is only used if you want to clear the configuration to set a new one like when you already have HA defined and want to move ap's to a different controller.  Using this, you want to make sure you clear out the controllers that the ap's are not joined to first, or else the ap's will move.  You then send the last command to set the ap joined controller to 0.0.0.0.
• Once the is done, you can then use the "ap high availability" tab to push our the new HA settings.

You can't just clear the HA configuration from the CLI, like what you can do on the GUI, that is why you define a bogus hostname and ip.