SMC Networks 8700S-130, Management Manual

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M
ULTICAST
F
ILTERING
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• IGMP Querier — 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 upstream 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 or PIM, to support IP
multicasting across the Internet.
Command 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: Enabled)
• 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: Enabled)
• IGMP Query Count — Sets the maximum number of queries issued
for which there has been no response before the switch takes action to
drop a client from the multicast group. (Range: 2-10, Default: 2)
• IGMP Query Interval — Sets the frequency at which the switch
sends IGMP host-query messages.
(Range: 60-125 seconds, Default: 125)
• IGMP Report Delay — Sets the time between receiving an IGMP
Report for an IP multicast address on a port before the switch sends
an IGMP Query out of that port and removes the entry from its list.
(Range: 5-25 seconds, Default: 10)
• IGMP Query Timeout — The time the switch waits after the
previous querier stops before it considers the router port (i.e., the
interface which had been receiving query packets) to have expired.
(Range: 300-500 seconds, Default: 300)