If you are specifying a specific "node" with an IP address in the SNMP Configuration (community names, timeout, and etc.) that is a router, does netmon actually check the status of each interface (ICMP)? Or does it only check only the specified IP address?
Netmon will get info on all the interfaces from the router via SNMP, assuming the community string is configured correctly to allow this. It can then do a periodic status poll, via ICMP on each interface that has an IP address.