Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 731)

IGMP and IGMP Snooping Introduction
Software Reference for x310 Series Switches
C613-50046-01 REV A AlliedWare Plus TM Operating System - Version 5.4.4C 30.5
IGMP Snooping and Querier configuration
example
This example describes the configuration of IGMP Snooping on an Allied Telesis managed
x310 Layer 2 switch (Switch 1) and the configuration of IGMP Querier (Switch 2). The
interface port1.0.6 is configured as a multicast router port. Host A and Host B are both
members of the same multicast group.
To enable IGMP Snooping on an interface:
■ Enable IGMP Snooping globally, if necessary. IGMP Snooping is enabled by default.
■ Enable IGMP Snooping on the desired interfaces, if necessary. IGMP Snooping is
enabled on all interfaces by default.
■ Statically configure ports that are connected to routers if necessary.
Figure 30-2: IGMP Snooping configuration example
As a result of this configuration:
■ Membership reports are generated by hosts. The IGMP Snooping switch will forward
the membership reports to its router port. Queries received by the IGMP Snooping
switch from the IGMP Querier on port1.0.6 are forwarded by the IGMP Snooping
switch.
■ Because Host A and Host B are members of the same multicast group, the switch does
not notify the IP IGMP routing device (IGMP Querier) when Host A leaves the group,
because the group still has another member Host B remaining. When Host B also
leaves the group, the switch forwards the leave message to the IP IGMP Querier.
■ The addition of a static mrouter port is only required when there is no upstream IGMP
querier or an upstream router does not send topology discovery or maintenance
messages (like IGMP General Queries or OSPF Hello packets).
■ In this example, the configuration of a static mrouter port on port1.0.6 is provided to
illustrate the
ip igmp snooping mrouter command. However, this command would
probably not be necessary, since the switch should dynamically set port1.0.6 to be an
mrouter port as it receives IGMP Queries arriving from the IGMP Querier attached to
port1.0.6.
igmpsnoop_1
Switch 1
Switch 2 port1.0.1
IGMP Querier IGMP Snooping Switch
port1.0.1 port1.0.6
port1.0.2
Host A Host B