As we are approaching the launch of SCOM 2012, it will come with the ability to monitor network devices. Question is.. what is the supported devices? In a nutshell, SCOM 2012 can monitor network devices that support SNMP, and can provide port monitoring for devices that implement interface MIB (RFC 2863) and MIB-II (RFC 1213) standards
The list of supported network devices can be found here: http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=26831
This list may change upon the General Availability of SCOM 2012.
Next Question is how about devices which do not meet the RFC MIB requirements? well it simply means that by default SCOM will not auto monitor the port monitoring for those devices. This can be overcome by creating custom monitors via the SCOM console