Installation guide

4-160 Motorola RF Switch System Reference Guide
• One router periodically broadcasts IGMP query messages onto a link
• Hosts respond to the query messages by sending IGMP report messages indicating their group
memberships
• All routers receive the report messages and note the memberships of hosts on the link
• If a router doesn't receive a report message for a particular group for a period of time, the router assumes
there are no more members of the group on the link
The IGMP Snooping screen is partitioned into two tabs supporting the following activities:
• IGMP Snooping Configuration
• IGMP Snoop Querier Configuration
4.11.1 IGMP Snooping Configuration
To view and configure IGMP snooping:
1. Select Network > IGMP Snooping from the main menu tree.
2. Select the IGMP Snoop Config tab.
3. Optionally select the Snoop Enable option.
When IGMP snooping is enabled, the switch analyses all the IGMP packets between hosts connected to
the switch and multicast routers. When a switch hears an IGMP report from a host for a given multicast
group, the switch adds the host's port number to the multicast list for that group. When the switch hears
an IGMP leave, it removes the host's port from the table entry. When enabled, a green checkmark
displays as opposed to a red “X” designating the snoop as disabled.
4. Optionally select the Unknown Multicast Forward option.
This will allow the broadcast of multicast traffic to all the ports in a broadcast domain (LANs), regardless
of whether the hosts were interested in that traffic or not.
5. Select Apply to save the changes to the Snoop Enable and Unknown Multicast Forward options.