3Com 10014298 manual Configuring the Limit of Igmp Groups on an Interface

120CHAPTER 6: MULTICAST PROTOCOL

query router receives the IGMP Membership Report message within the defined period (equal to robust-value seconds), it continues to maintain the membership of this group. When the IGMP query router receives no IGMP Membership Report messages from any hosts within the defined period, it perceives a timeout and stops membership maintenance for the group.

Perform the following configuration in VLAN interface view.

Table 124 Configure the Times of Sending IGMP Group-Specific Query Packet

Operation	Command
Configure the times of sending IGMP	igmp robust-count robust-value
Group-Specific Query packet
Restore the times of sending IGMP	undo igmp robust-count
Group-Specific Query packet to the default
value

By default, the robust-value is 2.

This command is only available on an IGMP query router running IGMP v2. For a host running IGMP v1, this command cannot take effect, because the host may not send the IGMP Leave message when it leaves a group.

Configuring the Limit of IGMP Groups on an Interface

You limit the number of multicast groups, from 0 to 1024, on an interface using the following configuration.

Perform the following configuration in VLAN interface view.

Table 125 Configure the Limit of IGMP Groups on an Interface

Operation	Command
Configure the limit of IGMP groups on an	igmp group-limit limit
interface
Restore the limit of IGMP groups on an	undo igmp group-limit
interface to the default value

Configuring a Router to be a Member of a Group

Usually, the host operating IGMP will respond to IGMP query packet of the multicast router. In case of a response failure, the multicast router will consider that there is no multicast member on this network segment and will cancel the corresponding path. Configuring one interface of the router as a multicast member can avoid such a problem. When the interface receives an IGMP query packet, the router will respond, ensuring that the network segment is connected and can receive multicast packets.

Perform the following configuration in VLAN interface view.

Table 126 Configure a Router to Be a Member of a Group

Operation	Command
Configure a router to be a member of a	igmp host-join group-addressport
multicast group (VLAN interface view)	{ interface_type interface_num
	interface_name } [ to { interface_type
	interface_num interface_name } ]