Adding a Host to System Center Virtual Machine Manager 2008 (SCVMM 2008) fails with a variation of Error (2916):
Cause: Specific content is being filtered by a non-Windows firewall. The firewall could be software installed on either the SCVMM 2008 Server or the Host that is being added. More likely, there is a hardware appliance firewall on the network between the two communicating servers.
For more information, refer KB2465160 - Add Host or other action fails with (2916) 0x80338126 in System Center Virtual Machine Manager 2008.