84 Switch Features
Layer 3 Multicast Features
For information about configuring L3 multicast features, see "Managing IPv4 
and IPv6 Multicast" on page 1167.
Distance Vector Multicast Routing Protocol
Distance Vector Multicast Routing Protocol (DVMRP) exchanges probe 
packets with all DVMRP-enabled routers, establishing two way neighboring 
relationships and building a neighbor table. It exchanges report packets and 
creates a unicast topology table, which is used to build the multicast routing 
table. This multicast route table is then used to route the multicast packets.
Internet Group Management Protocol
The Internet Group Management Protocol (IGMP) is used by IPv4 systems 
(hosts and routers) to report their IP multicast group memberships to any 
neighboring multicast routers. PowerConnect 8000/8100-series switches 
perform the “multicast router part” of the IGMP protocol, which means it 
collects the membership information needed by the active multicast router.
IGMP Proxy
The IGMP Proxy feature allows the switch to act as a proxy for hosts by 
sending IGMP host messages on behalf of the hosts that the switch 
discovered through standard IGMP router interfaces. 
Protocol Independent Multicast—Dense Mode
Protocol Independent Multicast (PIM) is a standard multicast routing 
protocol that provides scalable inter-domain multicast routing across the 
Internet, independent of the mechanisms provided by any particular unicast 
routing protocol. The Protocol Independent Multicast-Dense Mode (PIM-
DM) protocol uses an existing Unicast routing table and a Join/Prune/Graft 
mechanism to build a tree. PIM-DM creates source-based shortest-path 
distribution trees, making use of reverse path forwarding (RPF).