Interlogix NS3500-28T-4S User Manual - Manual (Page 164)

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Figure 4-7-2 Properties Information Page Screenshot
The page includes the following fields:
Object Description

Unknow Multicast Action Display the current unknown multicast action status.
 Forward Method For IPv4 Display the current IPv4 multicast forward method.
 Forward Method For IPv6 Display the current IPv6 multicast forward method.
4.7.2 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 IGMP is also used to periodically check the multicast group for members that are no
longer active.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