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4.8 Multicast
4.8.1 IGMP Snooping
The
Internet Group Management Protocol (IGMP)
lets host and routers share information about multicast groups memberships.
IGMP snooping is a switch feature that monitors the exchange of IGMP messages and copies them to the CPU for feature
processing. The overall purpose of IGMP Snooping is to limit the forwarding of multicast frames to only ports that are a member of
the multicast group.
About the Internet Group Management Protocol (IGMP) Snooping
Computers and network devices that want to receive multicast transmissions need to inform nearby routers that they will become
members of a multicast group. The
Internet Group Management Protocol (IGMP)
is used to communicate this information. IGMP
is also used to periodically check the multicast group for members that are no longer active.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 of the
multicast groups that have active members. The information received from IGMP is then used to determine if multicast packets
should be forwarded to a given sub network 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, packets will not be forwarded to that sub
network.
Figure 4-8-1:
Multicast Service
Summary of Contents for NS3702-24P-4S
Page 1: ...NS3702 24P 4S User Manual P N 1072832 REV 00 01 ISS 14JUL14 ...
Page 102: ...102 Figure 4 5 4 LACP Port Configuration Page Screenshot ...
Page 119: ...119 Figure 4 6 4 VLAN Membership Status for Static User Page Screenshot ...
Page 124: ...124 Figure 4 6 6 Private VLAN Membership Configuration page screenshot ...
Page 140: ...140 Figure 4 6 21 Group Name to VLAN Mapping Table Page Screenshot ...
Page 164: ...164 Figure 4 8 2 Multicast Flooding ...
Page 184: ...184 Figure 4 8 15 MLD Snooping Port Group Filtering Configuration Page Screenshot ...
Page 204: ...204 Figure 4 9 6 QoS Egress Port Tag Remarking Page Screenshot ...
Page 209: ...209 QoS Class QoS Class value can be any of 0 7 DPL Drop Precedence Level 0 1 ...
Page 251: ...251 Figure 4 11 3 Authentication Method Configuration Page Screenshot ...
Page 286: ...286 Figure 4 11 11 RADIUS Server Configuration Screenshot ...
Page 290: ...290 Figure 4 11 17 Add User Properties Screen Figure 4 11 18 Add User Properties Screen ...
Page 298: ...298 non committed changes will be lost ...
Page 349: ...349 Figure 4 16 2 PoE Configuration Screenshot ...