I have 2 mailbox, 2 hub transport/CAS in my enviroment. I installed the NLB for both transport/cas servers and set up the CAS array by doing the Get-MailboxDatabase | Set-MailboxDatabase -RPCClientAccessServer "myserver.mydomain.com" and everything works correctly. The problem after that is that when my second hub transport server is powered on that some people can connect to outlook and some people cant. I went around and pointed those users to cas array ip address and it says that exchange is offline. If i point them straight to the first cas server it converts it to the cas array and lets them connect.