Igmp Querier - Fujitsu XG0224 User Manual

XG Series User's Guide
4.8.4

IGMP Querier

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.
IGMP General Query
IGMP General Query
MAC
MAC
Destination IP : 224.0.0.1
Destination IP : 224.0.0.1
Group IP
Group IP
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.
• Generally, IGMP Querier uses "0.0.0.0" for the source IP address when sending a Query message.
Note
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.
Multicast Server
XG

IGMP Querier

: 0100.5E01.0001
: 0100.5E01.0001
: 0.0.0.0
: 0.0.0.0
Port 1 Port 2
Terminal 1
IGMP Querier
81
Chapter 4 Switch Functions and their Configuration
Port 3
Terminal 2 Terminal 3
IGMP Snooping