ActiveSync session is time out on Exchange 2013 (2nd CAS)

Hi all,

I really need a hand here. I need some advice regarding ActiveSync problem. I have2 x Exchange Server 2013. I have published the ActiveSync via ISA 2006, and the publishing pointed toServer 1. The rule is test successfully. I have mailboxes from exchange 2007, which were migrated successfully to both of the new exchange server.

My problem is, the user mailbox from Server 1 is able to setup and sync their mailbox via activesync, but the user onServer 2 cannot their exchange mailbox via active sync (any device), prompted error is "Unable to connect to the server".

Then, on each of the server, i tried to access the active sync URL

Server 1: https://server1fqdn/Microsoft-Server-ActiveSync <= works fine, logon prompted

Server 2: https://server2fqdn/Microsoft-Server-ActiveSync <= as per guessed, keep loading without result (time out)

I've tried to disable and enable ActiveSync on user mailbox on Server 2 without success, have compared the IIS setting on Server 1 and Server 2, they are exactly the same. I cannot find any suspicious warning or error on Server 2 eventviewer.

Have anyone got this issue? Any advice.

Thanks!