If this object is set to 'true', then when the router receives a request to leave a group or source, it immediately updates the routing table without running a timer. If mgmdRouterInterfaceExplTracking is also 'true' then it only leaves immediately when the last host leaves. If the mgmdRouterInterfaceQryBefImmdLv object is 'false', then the router does not issue a 'last member' query. This behavior is only useful when the interface has a single connected host. If the mgmdRouterInterfaceQryBefImmdLv is 'true', then the router also issues a last member query, with Max Response Time defined by the mgmdRouterInterfaceLstMemQryIvl option. This behavior is useful in scenarios where it is important for the router to leave the group quickly, even though there is the possibility of a second connected host that still needs to be joined to the group or source.