3Com Switch 7750 Configuration Guide

GMRP CONFIGURATION

GMRP Overview GMRP (GARP Multicast Registration Protocol), based on GARP, is used for

maintaining multicast registration information of the switch. All GMRP-capable

switches can receive multicast registration information from other switches,

dynamically update local multicast registration information, and send their own

local multicast registration information to other switches. This information

switching mechanism keeps consistency of the multicast information maintained

by every GMRP-supporting device in the same switching network.

A host sends a GMRP Join message, if it is interested in joining a multicast group.

After receiving the message, the switch adds the port on which the message was

received to the multicast group, and broadcasts the message throughout the

VLAN where the receiving port resides. In this way, the multicast source in the

VLAN gets aware of the existence of the multicast group member. When the

multicast source sends multicast packets to a group, the switch only forwards the

packets to ports connected to the members of that group, thereby implementing

Layer 2 multicast in the VLAN.

Configuring GMRP The main tasks in GMRP configuration include:

■ Enable GMRP globally

■ Enable GMRP on a port

GMRP must be enabled globally before it is enabled on a port.

Enabling GMRP Globally

Enabling GMRP on the

Port

Perform the following configuration in Ethernet port view.

Table 330 Enable GMRP globally

Operation Command Description

Enter system view system-view -

Enable GMRP globally. gmrp Required

Disabled by default.

Table 331 Enable/Disable GMRP on the port

Operation Command Description

Enter system view system-view -

Enter Ethernet port view interface interface-type

interface-number

Enable GMRP on the port gmrp Required

Disabled by default.