User Manual
UMN:CLI
V8102
485
To enable the immediate leave feature on a current interface, use the following command.
Command
Mode
Description
ip igmp immediate-leave group-
list
{
<
1-99> | <1300-1999> |
WORD
}
Interface
[VLAN]
Enables the IGMP immediate leave.
1-99: IP standard access list
1300-1999: IP standard access list (extended range)
WORD: access list name
no ip igmp immediate-leave
Disables the IGMP immediate leave.
Use this command only on IGMPv2 and IGMPv3 interfaces to which one IGMP host is
connected. If there is more than one IGMP host connected to a network segment through
the same interface, and a certain host sends a leave group message, the router will re-
move all hosts on the interface from the multicast group. The router will lose contact with
the hosts that should remain in the multicast group until they send join requests in re-
sponse to the router's next general query.
10.1.3
IGMP Version 3
IGMP version 3 provides support for the source filtering, which is to receive multicast traf-
fic for a group from specific source addresses, or from except specific source addresses,
allowing the Source-Specific Multicast (SSM) model.
The source filtering is implemented by the major revision of the membership report.
IGMPv3 membership reports contain two types of the record: current-state and state-
change. Each record specifies the information of the filter mode and source list. The re-
port can contain multiple group records, allowing reporting of full current state using fewer
packets.
The V8102 runs IGMPv3 by default, and there are no additional IGMPv3 parameters you
need to configure. IGMPv3 snooping features are provided.
IGMPv3 Messages
There are two types of IGMPv3 messages of concern to the host-router interaction as
shown below:
•
Membership query
A multicast router determines if any hosts are listening to a group by sending mem-
bership queries. There are three variants of the membership queries.
–
General query
: This is used to determine if any hosts are listening to any group.
–
Group-specific query
: This is used to determine if any hosts are listening to a par-
ticular group.
–
Group-source-specific query
: This is used to determine if any hosts are listening
to a particular group and source.
•
Version 3 membership report
This is used by hosts to report the current multicast reception state, or changes in the
multicast reception state, of their interfaces. IGMPv3 membership reports contain a
group record that is a block of fields containing information of the host's membership
in a single multicast group on the interface from which the report is sent. A single re-
port may also contain multiple group records. Each group record has one of the fol-
!