About Igmp - Motorola BSR 2000 Configuration And Management Manual

Release 1.0

About IGMP

IGMP manages the membership of hosts and routers in multicast groups. IP hosts use
IGMP to report their multicast group memberships to any immediately neighboring
multicast routers. Multicast routers use IGMP to learn, for each of their attached
physical networks, which groups have members.
IGMP is an integral part of IP and must be enabled on all routers and hosts that want
to receive IP multicasts.
For each attached network, a multicast router can be either a querier or a non-querier.
The querier router periodically sends general query messages to solicit group
membership information. Hosts on the network that are members of a multicast group
send report messages. When a host leaves a group, it sends a leave group message.
IP hosts use IGMP to report their group membership to directly connected multicast
routers. IGMP uses class D IP addresses for its group addresses that can range from
225.0.0.0 to 239.255.255.255.
The following multicast addressing rules apply to IGMP:
Note: IGMP recognizes the physical interfaces on which an IGMP query
message has been received or which have been statically configured. When
a multicast packet is forwarded, the packet will skip any physical interface
that has no IGMP association with the corresponding multicast group.
526360-001-00 Rev. B
Enabling IGMP
Controlling Access to IP Multicast Groups
Changing the IGMP Version
Modifying the IGMP Host-Query Message Interval
Specifying the IGMP Querier Time-out Interval
Changing the Maximum Query Response Time
Configuring the BSR as a Static Multicast Group Member
The 224.0.0.0 IP address is guaranteed not to be assigned to any group.
The address 224.0.0.1 is assigned to all systems on a subnetwork.
The address 224.0.0.2 is assigned to all routers on a subnetwork.
Configuring IP Multicast Routing
MGBI 9-9