Select an ADVA (Adtran) FSP 3000 R8 as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and locate f3TimeClockTimeInHoldover under the f3TimeClockEntry branch of F3-SYNC-MIB, selecting the specific row/instance you want to monitor since this is a table column, then select it and click OK. It reports how many seconds the network element's timing clock has been running in holdover — i.e. free-running without a valid external reference. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is an Integer32-type OID, Value bounds is the most useful condition here — trigger an alert if the holdover duration exceeds a few minutes (e.g. 300 seconds), since prolonged holdover risks clock drift affecting synchronization-dependent services. Click Finish to create the monitor; you can adjust any parameter later.