Hello Hussain Thanks for sharing the link with me, My question is "I have a server in APAC which has all three roles installed MHC, i had also create a DAG 2 in APAC server. How do i configure the CAS or CAS array for end users in APAC. Presently the Mailbox Datbaase is configured to use the Local CAS sever Localserver1. In this case how to i plan for high availability for mailbox servers. If my APAC server goes down automatically users have to use USA server"

Im in planning to create a High avalability solution in my Organization, I have two sites, One in USA and second in APAC. Already i have CAS Array created in USA, All the users in USA are using array1 (DAG1). I have a server in APAC which has all three roles installed MHC, i also create a DAG 2 in APAC server. How do i configure the CAS or CAS array for end users in APAC. Presently the Mailbox Datbaase is configured to use the Local CAS sever Localserver1. In this case how to i plan for high availability for mailbox servers. If my APAC server goes down automatically ysers have to use USA server.

You can use; set-mailboxdatabase -id databasename -RpcClientAccessServer casarray.domain.local http://technet.microsoft.com/en-us/library/bb123971.aspx For HA and Site resiliency read through these articles and the design examples http://technet.microsoft.com/en-us/library/dd638121.aspx Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog