Cisco WLC HA with 2504 series

I already posted a tutorial about Cisco WLC HA with 5500er series but I want to show you how to configure an N+1 high availability system with 2504 WLC from Cisco. Our main WLC will be a Cisco 2504 AIR-CT2504-5-K9 (supports five access points) and a HA unit Cisco 2504 AIR-CT2504-HA-K9. Here is the basic-configuration of our test environment:

WLC1-management-IP: 192.168.101.240
WLC1-virtual-IP: 1.1.1.1
WLC1-Hostname: BiWLC1
WLC2-management-IP: 192.168.101.241
WLC2-virtual-IP: 1.1.1.1
WLC1-Hostname: BiWLC2
Software Version on both WLCs: 8.3.102.0
Field Recovery Image Version: 7.6.101.1

The virtual IP needs to be the same on both controller! Also the mobility domain name and the RF group name needs to be the same:

set the second WLC to be the HA SKU unit:

Now we will configure a mobility group. Take the mac-address of the virtual interface:

BiWLC1:

BiWLC2:

as you can see, the entries are mirrored. If you have configured everything correct, you will see the following entries in the trap logs:

Thu Sep 29 13:26:34 2016 Data path to mobility member 192.168.101.240 is up.
Thu Sep 29 13:26:26 2016 Control path to mobility member 192.168.101.240 is up.

or you can check it at Controller / Mobility Management / Mobility Groups. Data and control path needs to be up. Once, I had a problem where one path doesn’t came up. Just restart the second WLC and check again. To order the access points to change to BiWLC2 once the BiWLC1 goes down, we need to configure the High Availability options under Wireless / Access Points / Global Configuration:

Don’t be confused with “Back-up Primary Controller IP Adress”. This is the second WLC. “Back-up Secondary Controller IP” is the tertiary WLC. I also configure the WLCs directly in every AP “to be sure” :)

Do you want CLI commands for this? Ask me in the comments!