SMC Networks SMC7724M Management Manual page 113

Command Usage
• IGMP Snooping – This switch can passively snoop on IGMP Query
and Report packets transferred between IP multicast routers/switches
and IP multicast host groups to identify the IP multicast group
members. It simply monitors the IGMP packets passing through it,
picks out the group registration information, and configures multicast
filters accordingly.
• IGMP Query – A router, or multicast-enabled switch, can periodically
ask their hosts if they want to receive multicast traffic. If there is more
than one router/switch on the LAN performing IP multicasting, one
of these devices is elected "querier" and assumes the role of querying
the LAN for group members. It then propagates the service requests
on to any adjacent multicast switch/router to ensure that it will
continue to receive the multicast service.
Note: Multicast routers use this information, along with a multicast
routing protocol such as DVMRP, to support IP multicasting
across the Internet.
Fields and Attributes
• IGMP Status – When enabled, the switch will monitor network traffic
to determine which hosts want to receive multicast traffic. This is also
referred to as IGMP Snooping. (Default: Disabled.)
• Act as IGMP Querier – When enabled, the switch can serve as the
Querier, which is responsible for asking hosts if they want to receive
multicast traffic. (Default: Disabled.)
• IGMP Query Count – Sets the maximum number of queries issued
for which there has been no response before the switch takes action to
solicit reports. (Default: 2, Range: 2 - 10.)
• IGMP Query Interval – Sets the frequency (in seconds) at which the
switch sends IGMP host-query messages. (Default: 125,
Range: 60 - 125.)
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ULTICAST ONFIGURATION
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