HA licensing for the standby unit in 8540 WLC

[Muhammed Adnan]

Hello Experts, 

Since we do not have HA-SKU part number in 8540, how is the HA licensing facilitated on the standby unit?

In 5508 series controllers, the for the non HA-SKU part number the requirement for the standby unit was to run atleast 50 permanent licenses.

Do we have any such restriction in 8540 series controllers?

[Scott Fella]

The 5520/8540 do not have an HA sku. So you can choose which box will be the standby unit. Purchase the required license you need for the primary and that’s about it. 

[Muhammed Adnan]

Thanks Scott for the prompt response. 

So for running HA in 5520/8540, we just need to have the licenses required to be installed only on the unit decided as primary.

While the unit decided as standby in initial configuration can run 0 licenses and still form the HA pair with the primary running the licenses?

Is there any minimal license required count to be enabled on the primary controller to form an HA? or Can we have a scenario running as low as 20 licenses on the primary and 0 licenses on the standby of 8540 controller and still form an HA pair?

[Leo Laohoo]

The secondary unit needs to have 50 AP license.

[Scott Fella]

There is no minimum for the 5520/8540 since there is no HA sku. You purchase the right amount of AP license and register that on the primary serial number. These units have RTU license so you pick which unit you want to use as primary and which one will be the standby. 

The older model 5508, you needed a minimum of 50 AP license to enable it as a standby in SSO pair. 

[Saravanan Lakshmanan]

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-3/config-guide/b_cg83/b_cg83_chapter_0100.pdf

For high-availability (HA) controllers when you enable HA, the controllers synchronize with the enabled license count of the primary controller and support high availability for up to the license count enabled on the primary controller.