I have recently installed Exchange 2010 into our organisation. The existing install is Exchange 2007. My 2010 config is as follows:-
I have installed 2 Hub / CAS servers and used Windows load balancing to distribute connections.
I have 2 mailbox servers with a DAG.
Mail flow works perfectly (after some head scratching).
I created a couple of 2010 users for test.
I can connect via OWA and connect through Outlook if I manually configure the settings.
I can't connect via Outlook if i use autodiscover - it prompts for the user's password and tries to connect to a mailbox server, but the credentials are never accepted. I have set the rpcclientaccessserver setting for all mailboxes to the correct CAS servers (not the load balance name).
Also when I look from a 2010 mailbox at a 2007 mailbox's calendar I can see the availability of the user, however when I look from a 2007 account I can't see a 2010 user's calendar - it says Free/Busy information not available.
Any ideas would be gratefully accepted.