System information

Using the System Configuration Program
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IGMP Multicast Filtering
Multicasting is used to support real-time applications such as video conferencing 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 which want to receive the multicast register with their local multicast switch/
router. Although this approach reduces the network overhead required by a
multicast server, the broadcast traffic must be carefully pruned at every multicast
switch/router it passes through to ensure that traffic is only passed on the hosts
which 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 which received a
similar request to that group. It then propagates the service request on to any
neighboring multicast switch/router to ensure that it will continue to receive the
multicast service. (For more information, see “IGMP Protocol” on page 4-5.)
Configuring IGMP
This protocol allows a host to inform its local switch/router that it wants to receive
transmissions addressed to a specific multicast group. You can use the IGMP
Configuration screen to configure multicast filtering shown below.
Note: The default values are indicated in the sample screen.
IGMP Configuration
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IGMP Status : ENABLED
IGMP Query Count : 2
IGMP Report Delay (Seconds) : 10
<APPLY> <OK> <CANCEL>
Use <TAB> or arrow keys to move. <Enter> to select
Parameter Description
IGMP Status If enabled, the switch will monitor network traffic to determine which hosts want
to receive multicast traffic. This is also referred to as IGMP Snooping.
IGMP Query Count The maximum number of queries issued for which there has been no response
before the switch takes action to solicit reports. (Range 2 - 10.)
IGMP Report Delay The time (in seconds) between receiving an IGMP Report for an IP multicast
address on a port before the switch sends an IGMP Query out that port and
removes the entry from its list. (Range 5 - 30.)