DELL N3000 User Manual

Switch Feature Overview

For information about configuring L3 multicast features, see "Managing IPv4 

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.

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. Dell Networking series switches perform the 

“multicast router part” of the IGMP protocol, which means it collects the 

membership information needed by the active multicast router.

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 (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).

This feature is not available on N2000 switches.