Filter
Top Products
DES-7200 Configuration Guide Chapter 2 IPv6 Multicast
Configuration
2-1
2 IPv6 Multicast
Configuration
2.1 Overview
Traditional IP transmission allows one host to transmit packets to a single host
(unicast communication) or all hosts (broadcast communication). (Note that IPv6
no longer supports broadcast). Multicast, however, allows one host to send
packets to some hosts (also known as group members).
The multicast application consists of the sender and the receiver. The sender can
send multicast packets without needing to join a group. In contrast, the receiver
can receiver the multicast packets from the group only after joining the group.
Group members are dynamic. A host can join in or leave from a group at any time.
Furthermore, there is no limit on the position and number of group members. A
host can join in more than one group simultaneously if necessary. Consequently,
the active status and the number of members of a group vary with time.
The device maintains the routing table for forwarding multicast packets by running
IPv6 multicast routing protocol (for instance, PIM-SMv6) and learns the status of
group members on the direct segment by running the MLDv1/v2 protocol. The
device joins in an IPv6 multicast group by sending the MLD report message.
IPv6 multicast applies to one-to-many multimedia applications.
2.1.1 Implementation of IPv6 Multicast Routing
The IPv6 multicast routing protocol includes:
MLD: Runs between the multicast deivce and the host to learn the relation of
group members.
PIM-SMv6: Runs between the multicast devices to enable multicast packet
forwarding by setting up the multicast routing table.
The following figure illustrates the function of the multicast protocols used in IPv6
multicast packet forwarding: