c589b6fa_pen_Shortest_Path_First__OSPF___Description
[Type #] 6 [LSA Name] Group membership [Description] 
Used in a now obsolete multicast version of Multicast Open Shortest Path First (MOSPF). Most routers no longer support MOSPF; this LSA may be reassigned in the future.
Types of link-state advertisements (LSAs) used in Open Shortest Path First (OSPF)
Description