DFM doesn't process link down traps except to determine if a link is flapping. You will not see link down traps in the DFM Alerts and Activities Display. Instead, DFM will use SNMP and ICMP polling to determine if an interface goes down. This will not happen for all interface types, though. These PPP interfaces may be learned as dial-on-demand interfaces by DFM, and thus will not report when they go down. If these links should be up all the time, then you will need to customize an interface group in DFM to match these interfaces, then enable the desired threshold information for these interfaces. You will still not see link down traps in DFM, but DFM should show OperationallyDown events in AAD based on the polling it does.
