WLC 5508 need to Install IRCM Image for Secure Mobility Group

[redhat251]

Hi Dear concern ,

I have 5508 controller running with 8.5.151.0 ,,,I wanted to migrate 5508 to 9800 WLC,  planned to create a secure mobility group  between AireOS and 9800 Controllers so need to Install IRCM Image,

I have a some question ,

## After upload IRCM Image in the WLC 5508 its need to reboot? 

## How the AP rejoined with this controller?

## I have Mobility group in the WLC need to add WLC 9800 in this group is it possible? Or i have create new mobility group?  

[marce1000]

 - Checkout https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/213913-building-mobility-tunnels-on-catalyst-98.html#anc27 , 
  Yes , if you install a (the) needed special IRCM image for the 5508  it will need to reboot , 

 M.

[Scott Fella]

After you upload any AireOS image to a controller, a reboot is always required. So during the reboot, you will have to figure out how the AP’s will be upgraded depending on how many controllers you have. You will also need to add the 9800 to the same mobility group if you are going to be running the controllers in parallel. This will allow for roaming to happen until you have fully migrated over to the 9800.

[Rich R]

Also see https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-8/b_c9800_wireless_controller-aireos_ircm_dg.html and
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/config-guide/ConfiguringIRCM/b-configuring-inter-release-controller-mobility-in-wireless-deployments-supporting-aireos-and-catalyst-9800-controllers.html and
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_vewlc_mobility.html#t_configuring_inter_release_controller_mobility_gui.xml

Also take note of TAC recommended code versions and 9800 best practices guide in links below: