DELL N3000 User Manual

Managing IPv4 and IPv6 Multicast

recipient host. The IP routing protocols can route multicast traffic, but the IP 

multicast protocols handle the multicast traffic more efficiently with better 

use of network bandwidth.
Applications that often send multicast traffic include video or audio 

conferencing, Whiteboard tools, stock distribution tickers, and IP-based 

television (IP/TV).

IP multicast traffic is traffic that is destined to a host group. Host groups are 

identified by class D IP addresses, which range from 224.0.0.0 to 

239.255.255.255. When a packet with a broadcast or multicast destination IP 

address is received, the switch will forward a copy into each of the remaining 

network segments in accordance with the IEEE MAC Bridge standard. 

Eventually, the packet is made accessible to all nodes connected to the 

network.
This approach works well for broadcast packets that are intended to be seen or 

processed by all connected nodes. In the case of multicast packets, however, 

this approach could lead to less efficient use of network bandwidth, 

particularly when the packet is intended for only a small number of nodes. 

Packets will be flooded into network segments where no node has any interest 

in receiving the packet. The L3 multicast features on the switch help to 

ensure that only the hosts in the multicast group receive the multicast traffic 

for that group.
Multicast applications send one copy of a packet, and address it to a group of 

receivers (Multicast Group Address) rather than to a single receiver (unicast 

address). Multicast depends on the network to forward the packets to only 

those networks and hosts that need to receive them.