Event Type:ErrorEvent Source:MSExchange ADAccessEvent Category:General Event ID:2152Date:8/25/2007Time:1:30:51 PMUser:N/AComputer:MAIL-02Description:Process mmc.exe (PID=3928). An remote procedure call (RPC) request to the Microsoft Exchange Active Directory Topology service failed with error 1825 (Error 721 from HrGetServersForRole). Make sure that the Remote Procedure Call (RPC) service is running. In addition, make sure that the network ports that are used by RPC are not blocked by a firewall. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. I am asos getting an error when trying to get properties of the mailbox in Exchange management console. It is: an error happended while accessing AD Topologu service on the specified server "pasdex.pasd.wan". the error message: Microsoft Exchange Active Directory Topology Service cannot be contacted via RPC inteface, error 0x721. It was running command 'get-exchangeserver -status -idenity '3abd3-a8d3-4e77-8021-1e196a7aed36" the rpc sevice is running and set to automatic. I cannot stop the service, all is grayed out. thanks for any help Steve

Is "Microsoft Exchange Active Directory Topology Service" running

Yes, the MS exchange Active Topology service is running on both the nodes in the cluster under the log onof the domain admin.The startup isset to automatic on both nodes. Thanks, Steve

Please tell us how to solve this problem... The error message: Microsoft Active Directory Topology Service cannot contactedvia RPC interface, error 0x721,