Step-by-step to make the MS DTC working between IIS and SQL servers if there is a firewall between them:
· Enable the Network DTC Access on both IIS and SQL
http://support.microsoft.com/?kbid=555017 (Step 1)
· Specify the static port numbers for MSDTC on both IIS and SQL
http://support.microsoft.com/?id=250367
· Add extra registry entries for the RPC (if the entry is there, modify it; otherwise add a new entry)
http://support.microsoft.com/?id=250367
· Open the static port numbers for MSDTC specified above (e.g. TCP 5000 – 5030) and port TCP 135 both ways between IIS and SQL servers on the firewall
· Open the port number that is used by MS SQL inbound to SQL server (e.g. TCP 1433)
· Configure the MSDTC Security setting
http://blogs.msdn.com/florinlazar/archive/2004/06/18/159127.aspx
Note: No Authentication Required radio box is selected because IIS and SQL are not running on Windows Domain Authentication
· Make sure IIS and SQL can resolve their name using NetBIOS (use hosts file) or DNS
http://support.microsoft.com/?kbid=555017 (Step 4)
· Disable RPC Security for MSDTC Service on SQL server
http://support.microsoft.com/?kbid=555017 (Step 5)
· Test the DTC communication with DTCPing tool
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q306843
