The time remaining until the local router will assume that
there are no longer any MGMD version 2 members on the IP
subnet attached to this interface. This entry applies to
both IGMP and MLD hosts. Upon hearing any MGMDv2
Membership Report, this value is reset to the group
membership timer. Assuming no MGMDv1 hosts have been
detected, the local router does not ignore any MGMDv2 Leave
messages for this group that it receives on this
interface.