Allied Telesis AR400 - Manual (Page 61)

Page 61 | AlliedWare™ OS How To Note: IGMP
IGMP fast leave > Example
IGMP fast leave
IGMP Fast Leave enhances your control over router or switch bandwidth. Enabling Fast Leave
tells IGMP snooping to stop the transmission of a group multicast stream to a port as soon as
it receives a Leave message on that port. No timeouts are observed.
Ordinarily, when IGMP snooping sees a Leave message, it waits for a Membership Query
message before setting the entry timeout to 2 seconds. Fast Leave tells IGMP to drop the
entry from the port as soon as the Leave message is seen. For this reason, Fast Leave should
only be configured on interfaces that have one clien t per port.
Availability IGMP Fast Leave is available in Software Version 2.7.5 or later. In Software Versions
earlier than 281-03 and 2.9.1, configure it by using the command:
set igmpsnooping fastleave={on|off} interface=vlanx
In Software Versions 281-03 and 2.9.1, the syntax changed to make it consistent with
Query Solicitation . Therefore, the above syntax is still valid but the recommended syntax is
now:
set igmpsnooping vlan=vlanx fastleave={on|off}
Software Version 291-08 introduced multiple mode for Fast Leave. See "Multiple host
mode for fast leave" on page 67 .
Example
This example uses the same network configuration as "IGMP snooping" on page 9 . For
convenience, the diagram is reproduced below.
Multicast Server
AT-8948
Switch 1:
Querier
Rapier 24i
Switch 2:
Snooper
Client 1
Rapier 24i
Switch 3:
Snooper
Client 2
port 1
port 2 port 3
port 25 port 25
port 26 port 26
port 50
(blocked by STP)
port 49
igmp-snooper.eps