Running 9800 and 5520 WLC's in parallel for upgrading a site.

[RGilbert]

I am upgrading 2 5520 controllers HA, and 2 Guest Anchors to 2 9800L's in HA and 2 9800 Guest Anchors.  We have a 3502's and 3800's in environment now.  Upgrading to 9130's I am looking for the best way to upgrade and have them possibly run in parallel for this 2 or 3 day process.  I do know the 3500 series AP's are not supported in the 9800 WLC's which is the only reason why I am trying to do this.  Any ideas on this would be appreciated.  

[Scott Fella · Accepted solution]

Just make sure you have mobility configured so that roaming is supported between the two.  Make sure that the 9800's are working fine and before you start moving or adding ap's to the new system.  I don't see any issue with running both, as long as devices don't start joining the other controller.  So make sure you have the high availability set first before anything.

[RGilbert]

Always appreciate the knowledge Scott.  I will make sure the 5520 AP's have the current controllers IP in Primary and keep secondary empty.  Using DNS for 9800 AP for the 9130's