Create a new backup interface group from polling and thresholds. (You may already see backup in interface groups.)
- In setting Tab: Add backup interface support or dial-on-demand
- In Priorities Tab: Move backup to the top of the list higher than ethernet
- In Matching Criteria: Enable Type with Value *ISDN* (It may already be there.)
Enable MaximumUptime set Value to 0 (You need to add this.) - Apply Changes
- Reconfigure
The new backup interface group should populate with members whose type is "ISDN". This will also clear the down alarms associated with these interfaces in the monitoring console. By setting MaximumUptime value to 0, it will result in not showing root cause and no alarm on it.