10G Core Routing Switch User Manual
陈泽科技有限公司
- - 68 - -
www.stephen-tele.com
II. Leaving group mechanism
In IGMP Version 1, hosts leave the multicast group quietly without informing the multicast router. In this case, the
multicast router can only depend on the timeout of the response time of the multicast group to confirm that hosts
leave the group. In Version 2, when a host is intended to leave, it will send a leave group message if it is the host who
responds to the latest membership query message.
III. Specific group query
In IGMP Version 1, a query of a multicast router is targeted at all the multicast groups on the network segment, which
is known as General Query. In IGMP Version 2, Group-Specific Query is added besides general query. The destination IP
address of the query packet is the IP address of the multicast group. The group address domain in the packet is also
the IP address of the multicast group. This prevents the hosts of members of other multicast groups from sending
response messages.
IV. Max response time
The Max Response Time is added in IGMP Version 2. It is used to dynamically adjust the allowed maximum time for a
host to response to the membership query message.
IGMP Configuration
1) IGMP basic configuration includes:
Enabling multicast routing
Enabling IGMP on an interface
2) IGMP advanced configuration includes:
Configuring the IGMP version
Configuring the interval of sending IGMP Group-Specific Query packet
Configuring the times of sending IGMP Group-Specific Query packet
Configuring the limit of IGMP groups on an interface
Configuring a router to join specified multicast group
Controlling the access to IP multicast groups
Configuring the IGMP query message interval
Configuring the IGMP querier present timer
Configuring the maximum query response time
Deleting IGMP Groups Joined on an Interface
Enabling Multicast routing
Enable multicast first before enabling IGMP and the multicast routing protocol.
Beginning in privileged EXEC mode, follow these steps to enable IP multicast routing.
Command
Purpose