I'm in the process of migrating from Exchange 2010 to 2013.  I've stood up two new 2013 servers, both have CAS and Mailbox roles on each.  

DAG:

I've split our mailbox databases between the two servers, configured a DAG, and have standby copies of each database on the alternate mailbox server.

CAS HA:

Since I have the CAS and Mailbox roles installed on the same server I can'y utilize WLB, so I've configured mail.domain.com as our OutlookAnywhere internal hostname and in DNS I've added records for both Mailbox/CAS servers as mail.domain.com (DNS round-robin).

Are both of these HA methods support and ideal?

• Edited by DG1212 Monday, August 03, 2015 5:33 PM

Hi DG,

Thank you for your question.

This is a HA for single site. If you have multiple sites, we should deploy HA for multiple sites by the following link:

https://technet.microsoft.com/en-us/library/dd638129%28v=exchg.150%29.aspx

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim