Can I deploy 9800 CL on Azure to be HA to 5520 WLC on prem?

[atsetheodros]

I have two 5520 WLCs at two different data center currently on STANDBY HOT SSO and is it possible to add a third WLC 9800CL as HA form Azure? @marce1000

[marce1000 · Accepted solution]

 - No you can't , HA-SSO setups must be symmetrical and controller types can not be mixed either , 

 M.

[atsetheodros]

I have an upcoming controller upgrade, the two 5520s will be swapped with 9840. What architectural design do you recommend to have with adding 9800 CL on Azure on top of those on prem?

[marce1000 · Accepted solution]

  - The most fundamental is from https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9800-cl-wireless-controller-cloud/nb-06-cat9800-cl-cloud-wirel-data-sheet-ctp-en.html
  And look at Table 2 : when the controller is deployed in the public count , you can only have Flexconnect with local switching modes , 

 M.

[atsetheodros]

We are on private cloud space

[marce1000]

 - Ok, (look at tab for private cloud in the mentioned table)

 M.

[atsetheodros]

I get that, what is the best way to deploy the three WLCs (two 9840s on prem at two different location) and 9800 CL on cloud.

N+1 HA or Standby HOT with SSO (not sure even it is possible.)

[marce1000]

   - I would stick to a single HA-SSO pair only  , 

 M.

[Rich R]

You can mix and match but HA-SSO across data centres is generally not recommended because you need layer 2 connectivity between the WLCs.  But if you do it that way you could still add the cloud WLC as N+1 backup to the HA pair.

Or you could run them all separately as N+1 but of course you need to make sure you keep the config updated on all of them so that anything moving between them has consistent config.  You should also configure mobility between the N+1 members.