I have a two nodes DAG and each node contains 2 mailbox servers. My outlook flash a message of lost connection everytime I failover to passive node. It even show the message when I failover just one of the databases that my outlook not even connected to. Is this a normal behavior? I use CAS array and all my databases connect to the same RpcClientAccessServer which is my CAS array. I have Public Folders replicate through all 4 mailbox servers. 

Thanks for you help in advance. 

Cheers

Ying

For Exchange 2013?  That does not sound normal to me.

sorry I forgot to mention, it is Exchange 2010. 

You have posted in an Exchange 2013 forum.  The Exchange previous versions forums are here:  http://social.technet.microsoft.com/Forums/en-US/category/exchangeserverlegacy

For Exchange 2010, Outlook only talks to the mailbox server for public folders.  It could be that clients connected to that server are being interrupted in some way, but I wouldn't think it would happen in the scenarios you describe.

Theoretically is should not happen and that's why I need fix it somehow. I will post this in the other forum. Thanks