The value of tmnxVrrpHostUnreachableEventPriority specifies
the priority level associated with this event. When the
operational state of the event transitions to one of the
'set' states, this value will either be subtracted from the
in-use priority (if the event is a 'delta' event) or the
in-use priority will be explicitly overridden by this
priority value (if the event is an 'explicit' event).