3Com SuperStack 4, Руководство по настройке

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172 C
HAPTER
7: M
ULTICAST
P
ROTOCOL
The Switch 5500G-EI runs IGMP Snooping to listen to the IGMP messages and
map the host and its ports to the corresponding multicast group address. To
implement IGMP Snooping, the switch processes different IGMP messages as
shown in
Figure 41 .
Figure 41 Implementing IGMP Snooping
Router port aging time Time set on the router port aging timer. If the switch has not
received any IGMP general query messages before the timer
times out, it is no longer considered a router port.
Multicast group member port
aging time When a port joins an IP multicast group, the aging timer of
the port will begin timing. If the switch has not received any
IGMP report messages before the timer times out, it
transmits IGMP specific query message to the port.
Maximum response time When the switch transmits IGMP specific query message to
the multicast member port, the Switch 5500G-EI starts a
response timer, which times before the response to the
query. If the switch has not received any IGMP report
message before the timer times out, it will remove the port
from the multicast member ports
Table 176 Switching Terminology relevant to IGMP Snooping
Term Meaning
Internet
IGMP packets
A Ethernet Switch
running IGMP Snooping
A router
running IGMP
IGMP packets
Switch 5500 running
IGMP Snooping