I'm not sure what traps you expect to see. DFM is not a general-purpose trap receiver. It will process some SNMP traps, but most of the events it produces come from SNMP and ICMP polling. These events will only be generated for devices in a Known state.
If you are seeing devices drop to a Questioned state, make sure they are ICMP reachable (i.e. pingable) from the LMS server. Unlike other modules in LMS, DFM requires that all devices be pingable on their management interfaces (i.e. the IP address in DCR). If you have Windows Firewall enabled, you will need to explicitly allow ICMP echo requests outbound and ICMP echo replies inbound for DFM to function properly.
If you are using SNMPv3 on your devices, you must make sure each device has a unique engineID (use "show snmp engineID" to confirm). If there are any duplicates, you must remove the devices from DFM, set a unique engineID, reconfigure your SNMP users, then re-add the device to DFM.
