I've been desparately looking for a solution to this and two calls to blackberry have yielded nothing.
We have 2xCAS servers (Exchange 2010, so service packs or rollups) and we have a BES (soon to have 2 of these as well but I don't think it will affect my question). We also have a Barracuda load balancer.
Currently, we have the two CAS servers load balanced with the Barracuda so that all traffic from Outlook client is load balanced. The problem we have is that the BES is on the same subnet and when BES looks for the CAS array (that it gets from AD), it gets the virtual IP addresses of the load balancer. We've fixed this by installing DNS on the BES (host file would work too), but we don't think this is optimal. We cannot figure out (nor could Barracuda) how to route traffic from one subnet back to itself via the virtual IP (which is on a different subnet), without using specific ports.
There is a blank in the MAPI profile to add an exchange CAS server, but I can only add one and we need to add two.
Here are the options and order of desirability (in my boss's eyes, 1 being the most desirable):
1. Some unknown solution allowing us to keep BES and CAS configurations working as they are and have the load balancer route the traffic between each CAS
2. Some unknown solution allowing us to enter two different CAS servers on the BES such that it will at least be fault tolerant between the two (remember, we have to specify different DNS than AD would supply, or use IP address so that we can avoid the load balancer).
3. The current DNS solution we have
4. The host file solution
5. Static ports for all exchange-bound traffic (so that we can use TCP proxy on the load balancer)
6. Change the IP address of the BES to be on the same subnet as the VIP
My question here is mainly about option #2, but any help on the other points or different suggestions would be very appreciated.
Thanks!
