HP J9729A User Manual

1 Multimedia Traffic Control with IP Multicast (IGMP)
Overview
This chapter describes multimedia traffic control with IP multicast-Internet Group Management
Protocol (IGMP) controls to reduce unnecessary bandwidth usage on a per-port basis, and how to
configure it with the switch's built-in interfaces. For general information about IGMP, see “IGMP
general operation and features” (page 7).
NOTE: The use of static multicast filters is described in the chapter titled "Traffic/Security Filters"
in the Access Security Guide for your HP switch.
IGMP general operation and features
In a network where IP multicast traffic is transmitted for various multimedia applications, you can
use the switch to reduce unnecessary bandwidth usage on a per-port basis by configuring IGMP.
In the factory default state (IGMP disabled), the switch simply floods all IP multicast traffic it receives
on a given VLAN through all ports on that VLAN (except the port on which it received the traffic.)
This can result in significant and unnecessary bandwidth usage in networks where IP multicast
traffic is a factor. Enabling IGMP allows the ports to detect IGMP queries and report packets and
manage IP multicast traffic through the switch.
IGMP is useful in multimedia applications such as LAN TV, desktop conferencing, and collaborative
computing, where there is multipoint communication, that is, communication from one to many
hosts, or communication originating from many hosts and destined for many other hosts. In such
multipoint applications, IGMP is configured on the hosts, and multicast traffic is generated by one
or more servers (inside or outside of the local network.) Switches in the network (that support IGMP)
can then be configured to direct the multicast traffic to only the ports where needed. If multiple
VLANs are configured, you can configure IGMP on a per-VLAN basis.
Enabling IGMP allows detection of IGMP queries and report packets used to manage IP multicast
traffic through the switch. If no other querier is detected, the switch then also functions as the
querier. If you need to disable the querier feature, do so through the IGMP configuration MIB, see
“Configuring the querier function” (page 13).
NOTE: IGMP configuration on the switches operates at the VLAN context level. If you are not
using VLANs, configure IGMP in VLAN 1 (the default VLAN) context.
IGMP operating features
Basic operation
In the factory default configuration, IGMP is disabled. To enable IGMP
• If multiple VLANs are not configured:
Configure IGMP on the default VLAN (DEFAULT_VLAN; VID=1.)
• If multiple VLANs are configured:
Configure IGMP on a per-VLAN basis for every VLAN where this feature is to be used.
Enhancements
With the CLI, you can configure these additional options:
You can use the console to configure individual ports to any of the following states:Auto/blocked/forward
Auto (Default) Causes the switch to interpret IGMP packets and to filter IP multicast
traffic based on the IGMP packet information for ports belonging to a multicast
Overview 7

HP J9729A Specifications

General

Brand	HP
Model	J9729A
Category	Switch
Language	English