Wireless Access

Hello, I'm hoping to just gain clarification on the optimal design in Aruba OS 8 in this non "best practices" physical architecture. There are three separate university campuses, each with a single hardware 7xxx controller. There is also a virtual mobility master.

 

Is there an advantage here to cluster these physically separate controllers, or should we simply rely on LMS/backup-LMS config in the AP Groups? The controllers are not layer 2 adjacent, and we definitely want the APs to terminate on the local controller unless there is a failure.

So I believe creating three separate AP groups for the three sites and specifying the LMS/backup LMS is sufficient for this requirement.

 

The main point I'm asking is: would creating a layer 3 cluster significantly reduce failover time, or provide another benefit I'm not understanding? I don't want a clustering mechanism to kick in that would have APs terminating on the wrong controller, and so the AP Group basic LMS/backup LMS keeps things more static and controlled, from my understanding.

This my first ArubaOS8 deployment, so just trying to confirm that I'm not missing anything, thanks!

Clustering is only for controllers that share all client layer two vlans, period. If you have controllers at two different sites that do not share the same layer 2 client vlans, you should use LMS IP and backup LMS-ip. The strength of clustering is the ability to share client state amongst redundant controllers which makes AP failover almost "hitless" from the client perspective. If the client has to change ip addresses upon failover, there is no purpose for clustering because client state cannot be preserved if client IP addressing needs to change upon failover. Backup LMS IP should be used in that circumstance.

I hope that makes sense.