This read-write value, in centiseconds, sets how often GARP forces all of a port's dynamic VLAN registrations to be reconfirmed via a LeaveAll cycle. An admin shortens this interval in a rapidly changing VLAN environment where memberships need to be revalidated more often, at the cost of extra GVRP control traffic. For example, reducing the LeaveAll interval on a port serving frequently reconfigured VLANs ensures stale dynamic registrations are cleared out sooner than the default interval would allow.