We have a small Exchange 2010 DAG environment with 1 core site (site A) and 3 remote sites (sites B,C and D)
Site A has:
1 mailbox server, 1 CAS/HUB server and 1 CAS/HUB/Mailbox (with no mailboxes, purely for DAG voting)
Site B, C and D have:
1 CAS/HUB/Mailbox server
We have DAG replication running which is replicating the databases at sites B,C and D to Site A and the Site A databases to site D.
We cant put additional mail servers to the remote sites but in the event that the server fails we want disruption to users to be minimized. If we point the CAS Array for each site to point to a load balancer at the site and then have the load balancer load balance between the CAS at the site and the CAS servers at site A (favouring the local CAS using Source IP affinity of course) will that work or will it be a problem that the CAS its connecting to isnt part of the CAS array object when it points to Site A?
We would also be using the load balancer to failover the hub transport traffic from network scanners etc as well.