RPC server not available for TMG server

RPC server not available for TMG server

I am under to see the hardware details for my TMG server after doing a scan.
it says RPC server not available.
Do I need to create a policy to permit servicedesk to poll the TMG server.
I have already allowed port 9000 to go through.
what other port number must I permit ?

                  New to ADSelfService Plus?