Overview Of Igmp Snooping; Configuring Igmp Snooping; Switch Snooping Configuration - Symbol ES3000 Manual

12-2 ES3000 Advanced Concept Guide

12.1 Overview of IGMP Snooping

The Internet Group Management Protocol (IGMP) is an Internet protocol that allows an Internet
computer (Host) to report its multicast group membership to multicast routers. Multicasting allows
one computer on the Internet to send information to other computers that have identified themselves
as interested in receiving the information. For further information about IP multicast and IGMP, refer
to RFC 1112 and RFC 2236.
The ES3000 switch can "snoop" this messaging protocol to keep track of multicast groups and to
insure that multicast traffic is sent only to the appropriate ports within a VLAN.

12.2 Configuring IGMP Snooping

12.2.1 Switch Snooping Configuration

Use the IGMP Snooping Configuration page (IGMP Snooping
Snooping Config) to enable or disable IGMP snooping on the switch and set some global snooping
parameters. The page displays the following:
• IGMP Snooping Status: The global enabled or disabled status of IGMP snooping. The
administrator can select Enabled or Disabled. When Enabled, the switch detects IGMP
queries, reports, and manages multicast traffic through the switch for all VLANs. When
Disabled, the switch forwards traffic and disregards IGMP requests. To filter out snooping
on specific VLANs, set the VLAN filter; see "VLAN filtering" on page 3.
• Host Port Age-Out Time: The length of time, in seconds, the switch keeps a host in a
multicast group without receiving IGMP reports from the host. The value can be within the
range 130-1225. The default is 260 seconds.
• Router Port Age-Out Time: The length of time, in seconds, the switch keeps router port
entries without receiving IGMP queries from the router. Routers usually send protocol
advertisements every few seconds. The value can be within the range 60-600. The default
is 125 seconds.
• Report Forward Interval: The length of time, in seconds, that the switch waits before
forwarding an IGMP report to the router from a group from which it has previously sent a
report. The value can be within the range 0-25. The default is 5 seconds.
• Multicast Group Membership table: The table displays the ports within a VLAN that are
associated with a multicast group, which is specified by the Group Mac Address. If a host
IGMP Snooping Config IGMP