I decided to go with Kemp, I have the CAS Array built and configured, but am now stuck at how to point the CAS on the new exchange server to the Kemp virtual CAS Array. The instructions I’ve seen don’t make complete sense to me. I want to make sure I get this piece correct before I create the DAG.

Any clarity you can provide would be greatly appreciated.

Thanks

What is the best, fastest and easiest process to revert this setup back into a Single Exchange Server ?

All feedback much appreciated.

Yes.

Another question; can the new CAS array and DAG co-exist with the original Exchange 2010 server? What I mean is, can I build the new CAS array create the new DAG and test the migration of an email account to the new DAG database all the while having the original Exchange server online? What I want to test is the Outlook client after it is moved to the DAG to make sure the Outlook clients move to the new CAS array automatically.

Thanks

NLB is a feature of Windows Server. It is correct that NLB can’t be used if the servers are also DAG members. It can be used if the CAS roles are installed on separate servers.

However, I don’t recommend using NLB. It is not a good load balancing solution for Exchange. I recommend you use a third party load balancer or virtual load balancer from a vendor such as Kemp or F5. This will be a good investment for your future because Exchange 2013 and beyond make NLB an even worse choice than it already is.

Using NLB will mean a minimum of 4 Exchange servers. Using a load balancer will mean a minimum of 2 Exchange servers + the load balancer, a much better solution.

So, my recommendation is as before.

More specifically this:

Two or more Exchange Server 2010 Client Access Servers can be configured as a CAS array using NLB as long they are not also installed as Mailbox servers that are members of a Database Availability Group (DAG).

I’m confused.

I thought you could not have a load balancer on the same server as those running DAG?

If you have a single Exchange 2010 server with all the roles installed today, then the best path for you is to build a second server with all roles installed. You can then add a load balancer to the solution for CAS high availability, and make both servers members of a DAG for mailbox high availability.