There seems to be a number of questions asked about the Exchange 2013 - legacyexchangeDN and RpcClientAccessServer attribute when migrating from Exchange 2010 to Exchange 2013.

In Exchange 2010 when you had a CAS Array, the above two attributes were populated with the name you set up for your CAS Array.

However, in Exchange 2013, the ExchangeLegacyDN is not used for anything. Take note that in Exchange 2013 you don't have the CAS Array option anymore. If you want high availability on your Exchange 2013 CAS Servers then you need to look at a load balancer option like F5 or KEMP that has iRules/Rules on them that will take a server offline if a component fails or server fails.

If you want to check the above values you can do so using the following command:

  • Get-MailboxDatabase -Identity "DB Name" | fl

This will then give you all the information about the database but we interested in the two attributes as mentioned above: