Fujitsu P3NK-4452-01ENZD Manual De Usuario

XG Series User's Guide

Chapter 4 Switch Functions and their Configuration

IGMP Snooping

In a typical network configuration, the multicast router periodically sends out an IGMP General Query message to 
determine if any of the hosts on the network are members of any multicast groups. Receiving a response from a host 
ascertains its membership in a multicast group.

IGMP Querier is a function that acts as a proxy for a multicast router when one is not available in a network segment to 
send an IGMP General Query message to all hosts.

The Query interval is 126 seconds.

Upon reception of an IGMP Leave message, the device sends an IGMP Specific Query (GSQ) message to determine that 
the host is interested in leaving the group.

If an IGMP Specific Query message is sent 2 times and the host does not respond with an IGMP Report message, that host 
is removed.

Note

• Generally, IGMP Querier uses "0.0.0.0" for the source IP address when sending a Query message.

Since some client software does not return a response for a Query message with the source IP address being set 
to "0.0.0.0", it is recommended that an address other than "0.0.0.0" be used.

• If a multicast router exists on the network segment, the device does not send Query message even if IGMP 

Querier is valid.

XG

IGMP Querier

Terminal 1

Port 1

Port 2

Port 3

IGMP General Query

MAC                : 0100.5E01.0001
Destination IP : 224.0.0.1
Group IP         : 0.0.0.0

IGMP General Query

MAC                : 0100.5E01.0001
Destination IP : 224.0.0.1
Group IP         : 0.0.0.0

IGMP Querier

Multicast Server

Terminal 2

Terminal 3