TMG Monitoring through SCOM 2012

We need to monitor TMG 2010 through SCOM 2012 but unable to monitor , Agent monitor showing not monitored , i also following this article,

 http://www.windows-noob.com/forums/index.php?/topic/9355-tmg-2010-and-scom-2012/.

following event found on SCOM 

DCOM was unable to communicate with the computer VM105.ebmgroup.com.pk using any of the configured protocols; requested by PID      bb8 (C:\Program Files\Microsoft System Center 2012 R2\Operations Manager\Server\MonitoringHost.exe).

LOG Name :           System

Source :                  DistributedCOM

Event ID:                 10028

Level :                     Error

Task Category :      None

Keyword:                Classic