Each row entry in the vRtrIgmpGrpIfTable represents a group interface on
this router that participates in the IGMP protocol. An entry in
this table can be created or destroyed by an SNMP SET request to
vRtrIgmpGrpIfRowStatus. An attempt to destroy a row will fail if
vRtrIgmpGrpIfAdminState has not first been set to 'outOfService'.