Enterasys Matrix E6 5G102-06-G, User Manual

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IGMP Configuration Screen
Device Control Menu Screens 7-27
Field Descriptions
Refer to Table 7-13 for a functional description of each screen field.
7.8.1 IGMP Multicast Filtering
Multicasting is used to support real-time applications such as video conferences or streaming
audio. A multicast server does not have to establish a separate connection with each client. It
merely broadcasts its service to the network, and any hosts that want to receive the multicast
register with their local multicast switch. Although this approach reduces the network overhead
required by a multicast server, the broadcast traffic must be carefully pruned at every multicast
switch it passes through to ensure that traffic is only passed to the hosts that subscribed to this
service.
This switch uses IGMP (Internet Group Management Protocol) to query for any attached hosts
who want to receive a specific multicast service. The switch looks up the IP Multicast Group used
for this service and adds any port that received a similar request to that group. It then propagates
the service request on to any neighboring multicast switch to ensure that it will continue to receive
the multicast service.
( For more information about the use of IGMP snooping and multicast
filtering, refer to Appendix D .)
NOTE: The default values are shown in Figure 7-12 .
Table 7-13 IGMP Configuration Screen Field Descriptions
Use this field... To...
IGMP Status Enable or disable the switch that will monitor network traffic
to determine which hosts want to receive multicast traffic.
IGMP Query Count Set the time in minutes that must elapse before the switch
removes the port from an IGMP group. This timer is started
after the number of queries are missed as defined in the
IGMP Query Count.
IGMP Report Delay (Minutes) Set the number of queries that must be missed before the
IGMP Report Delay timer is started. This is used in
conjunction with the IGMP Report Delay to remove ports
from an IGMP group.