Planet IGS-801T [81/120] Multicast

User’s Manual of IGS-801M

4.7 Multicast

The Internet Group Management Protocol (IGMP) lets host and routers share information about multicast groups

memb P snooping i m to the

CPU for feature processing. The he forwarding of multicast frames to only

ports that are a member of the multicast group.

About the Internet Group Management Protocol (IGMP) Snooping

Compu etwork devices that they will

become members of a multicast group. The Internet Group Management Protocol (IGMP) is used to communicate this

inform is also used t at are no longer active. In the case

where there is more than one multicast router on a sub network, one router is elected as the ‘queried’. This router then

keeps track of the membership MP is

then used to determine if multic ork or not. The router can check,

using IGMP, to see if there is at least one member of a multicast group on a given subnet work. If there are no members

on a sub network, packet

erships. IGM s a switch feature that monitors the exchange of IGMP messages and copies the

overall purpose of IGMP Snooping is to limit t

ters and n that want to receive multicast transmissions need to inform nearby routers

ation. IGMP o periodically check the multicast group for members th

of the multicast groups that have active members. The information received from IG

ast packets should be forwarded to a given sub netw

s will not be forwarded to that sub network.

Figure 4-7-1 Multicast Service