Most of the SCOM Administrators and Consultants are aware of the list regarding the supported Network Devices which is available at Microsoft Download but this list doesn’t seems to be updated regularly.
System Center Operations Manager 2012 : Network Devices with Extended Monitoring Capability
https://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=26831
The easiest way to find out if a Network Device is supported by SCOM is to take the OID of the Component and search for it in the following directory : C:\Program Files\System Center Operations Manager 2012 R2\Server\NetworkMonitoring.
Below is an example using findstr to search for the OID for the CPU utilization variable on a Cisco device :
C:\Program Files\System Center Operations Manager 2012 R2\Server\NetworkMonitoring>
Findstr /I /S /C:".1.3.6.1.2.1.1.1.0" /M *.*
You can see that several files were returned that contain this string, which means the component is supported and should be discovered. If nothing is returned, then the component is not supported at that time.
Was the device discovered using ICMP-only ? If yes, then the availability of the device is all that will be monitored.
Good luck !