RAVENNA Networking Guide
V1.0/3
28
Network Switch Configuration
Multicast (with IGMP Snooping & Port Filtering)
3.
Select the
Edit
button beside the relevant vLAN entry in the
IGMP Snooping Table
to edit the IGMP
Querier settings - a dialogue box opens:
IGMP Snooping Status
- tick
Enable
.
IGMP Snooping is a technique used by network switches to control the forwarding of Multicast data packets. A
switch with IGMP Snooping will forward Multicast data packets only to the ports that are members of the
Multicast group. (Whereas, a switch without IGMP Snooping will broadcast Multicast data to all of its output
ports.) As a result, the volume of Multicast traffic will be significantly reduced if a network switch supports IGMP.
MRouter Ports Auto Learn
- tick
Enable
and enter the recommended
Default
values (e.g.
Query Robustness
=
2, Query Interval = 125
, etc.)
If your network contains multiple switches, you will need to configure Multicast router ports to allow Multicast
traffic and IGMP messages to be transmitted to other switches. This is achieved by enabling the
MRouter Ports
Auto Learn
options above. Once auto learning is enabled, no special multicast router port settings are required.
Immediate Leave
- tick
Enable
.
This option allows the switch to determine when an output port has left a Multicast group. If the option is not
enabled, then Multicast traffic can flood the output port continuously. Note that in other switches, this option may
be known as
Fast Leave
.
IGMP Querier Status
- tick
Enable
and set the
Querier Source IP Address
to either
Auto
or a specific IP
address (see note below).
IGMP Querier version
- select
IGMPv2
.
Multicast networks require an active querier to request the IGMP messages. There should be only
one active IGMP Querier in the network; if the IGMP Querier Status is set to
Auto
, then the querier
will be determined automatically. However, if you are using other switches (not in
Auto
mode), then
you must make sure that there is only one querier and enter the IP address of the Querier switch.
Otherwise, multiple IGMP messages will be sent.
