User Manual

495
Users Manual of XGS-6350-24X4C
and RFC3376. IGMP V1 supports only the function to record the multicast group members. IGMP V2 can
query the designated multicast group member, generates the leave message when an IGMP host leaves a
multicast group, and shortens the change delay of the group member. IGMP V3 has additional functions to
update and maintain the multicast group member IDs which correspond to the source host addresses. The
IGMP Router protocol of IGMP V3 is fully compatible with the host side of IGMP V1 and IGMP V2. MY
COMPANY’s switch software supports the IGMP Router protocols of the three IGMP versions.
You can configure the IGMP-Router function at different interfaces (the multicast routing protocol configured
on different interfaces can start up the IGMP-Router function) and different versions of IGMP can be run on
different interfaces.
Note that a multicast switch can start up the IGMP-Router function on only one of the ports that connect the
same network.
Run the following command in interface configuration mode to change the version of the IGMP-Router
protocol on a port:
Command Purpose
ip igmp versionversion_number
Changes the IGMP version running on
the current port.
50.3.2.2 Configuring IGMP Query Interval
No matter what version number of the current IGMP-Router protocol is, the multicast switch can send the
IGMP General Query message every a certain time on the port where the IGMP-Router function is started.
The transmission address is 224.0.0.1. The purpose of the multicast switch is to get the report message from
the IGMP host and therefore know which multicast group each IGMP host in the network belongs to. The
interval to send the General Query message is called as IGMP Query Interval. If the parameterIGMP Query
Interval is set to a big value, the switch cannot immediately receive the information about which multicast
group the current IGMP host belongs to. If the parameter IGMP Query Interval is set to a small value, the flow
of the IGMP message is to increase in the current network.
Run the following command in interface configuration mode to modify the IGMP query interval on a port:
Command Purpose
ip igmp query-intervaltime
Modifies the IGMP query interval on
the current interface (unit: second).
50.3.2.3 Configuring IGMP Querier Interval
As to version 2 and version 3 of the IGMP-Router protocol, if another switch that runs the IGMP-Router
protocol exists in the same network, you need to choose a querier. Querier stands for a switch that can send
the query message (In fact, it is a port of the switch where the IGMP-Router protocol is enabled). Normally,
one network has only one querier, that is, only one switch sends the IGMP Query message. There is no
querier choice for IGMP-Router V1 because the multicast routing protocol decides which switch to send the
IGMP Query message in IGMP-Router V1.
IGMP-Router V2 and IGMP-Router V3 have the same querier choice mechanism, that is, the switch with the