Hi All, I am trying to install Exchange 2010 CAS server rolle in Child domain but the installation fails. My envirnoment is of Multi Domain Structure and we have completed 1. Schema and Domain Prepare for all Domain. 2. Disabled Firewall on all DC and Exchange 3. IPv6 is disabled in registry. 4. User account which we are trying to install has Exchange Full Org Permission. Error log: Process MSEXCHANGEADTOPOLOGY (PID=1528). The site monitor API was unable to verify the site name for this Exchange computer - Call=DsctxGetContext Error code=8007077f. Make sure that Exchange server is correctly registered on the DNS server. Event ID 2501 Process MSEXCHANGEADTOPOLOGY (PID=1528). When updating security for a remote procedure call (RPC) access for the Microsoft Exchange Active Directory Topology service, Exchange could not retrieve the security descriptor for Exchange server object ESC-CAS-01 - Error code=8007077f. The Microsoft Exchange Active Directory Topology service will continue starting with limited permissions. Event ID 2604 Process MSEXCHANGEADTOPOLOGY (PID=1528). When initializing a remote procedure call (RPC) to the Microsoft Exchange Active Directory Topology service, Exchange could not retrieve the SID for account <WKGUID=1A9E39D35ABE5747B979FFC0C6E5EA26,CN=Microsoft Exchange,CN=Services,CN=Configuration,...> - Error code=8007077f. The Microsoft Exchange Active Directory Topology service will continue starting with limited permissions. Event ID 2601 Thanks in Advance. Nagaraj N

Post all the commands you ran on the server before the installation.` NLTest /DSGetSite and check if its give you the same child domain site or different.Gulab | MCTS-MCITP Messaging: 2010 | MCTS-MCITP Messaging: 2007 | MCC 2011 | Skype: Gulab.Mallah

Please verify if the problematic exchange server is the member of “Exchange servers” group Has the teaming NIC been used on the problematic server? Please use LDIFDE tool to dump the LDAP directory, and then display the dump in notepad to search for the owner of GUID (1A9E39D35ABE5747B979FFC0C6E5EA26) ldifde -f config.ldf -d "cn=configuration,dc=domain,dc=com" -p subtree Please run “DCDiag /v /a” and “NetDiag /v” to check the health of DC and connection to DC from the problematic exchange server James Luo TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi All, Thanks for all the suggestions. After troubleshooting found that the error was due to connectivity problem to GC servers in the site. Once this was solved we were able to install Exchange CAS server 2010 successfully. Thanks Nagaraj N