The revert command allows the clock to revert to a higher-priority reference if the current reference goes offline or becomes unstable.
If revertive switching is enabled, the highest-priority valid timing reference is used. If a reference with a higher priority becomes valid, a switchover to that reference is initiated. If a failure on the current reference occurs, the next highest reference takes over.
If non-revertive switching is enabled, the active reference always remains selected while its valid, even if a higher priority reference becomes available. If the active reference becomes invalid, a reference switchover to a valid reference with the highest priority is initiated. The failed reference is eligible for selection when it becomes operational.
config>system>sync-if-timing
revert