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