new wlc 9800 and 9120 migration

[as00001111]

Hi guys,

currently we are using a central wlc 5508 and AIR-LAP1142 access points with flex connect.

We got a new branch office where we have bought 9120AX access points for. Futhermore, we bought a C9800 WLC.

My idea is to setup the new wlc in parallel and connect the new access points to it.

The current 5508 and 1142 must stay.

Would a parallel setup work?

Thank you.

[Rafael E]

you need to set up the new 9800 so you can have 9120 APs register to the WLC. 

5508 does not support 9120. 

If this is a new remote branch there is no need for WLCs to talk to each other as APs are in different locations. 

If APs are on the same location as 1140 then you will have a problem as you need to run an IRCM image on 5508 so it can be able to talk to the 9800 but that is only available on 8.5 train code. 

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-8/b_c9800_wireless_controller-aireos_ircm_dg.html

Going to 8.5 is not an option for you as you have 1140 APs. So, I recommend setting up the AP on different locations so they can be managed independently otherwise communication with WLCs will not be possible with your current hw. 

[as00001111]

Hi Rafael, yes that's exactly what I want to do. I don't want to mix 9120 and 1140. My question is if both WLCs can run in parallel, but independent. If any problems occur?

[Rafael E]

they can run in parallel. 

[Scott Fella]

You always can have a parallel network in place, it’s the only way to really do a migration without a hard cut. The only thing you need to make sure of is that your discovery method doesn’t point to one or the other controller. You don’t want your 1142’s to try to join the new controller. This shouldn’t be a big deal especially if the 9800’s are on a different subnet and you have defined the high availability on each access point. Keep in mind that you can define mobility between the two because your 5508 is running 8.5. So when you migrate over, you either have to migrate all at once or possible areas at a time where roaming is not an issue.