Overview of MLD
Definition
Multicast Listener Discovery (MLD) is a protocol that manages IPv6 multicast members. The MLD protocol sets up and maintains memberships between IPv6 hosts and their directly connected multicast routers by exchanging MLD messages between them. MLD messages are encapsulated in IPv6 packets.
Purpose
IPv4 multicast effectively addresses the problem of point-to-multipoint data transmission. This technology efficiently transmits data from one point to multiple points over a network, saving network bandwidth and reducing network loads. The IPv4 multicast application is further enhanced in IPv6. MLD works on an IPv6 network in the same way the Internet Group Management Protocol (IGMP) works on an IPv4 network, but the two protocols define different message formats.
MLD defines how to maintain group memberships between multicast routers and hosts on a network segment. Figure 1 shows where the MLD protocol runs on an IPv6 multicast network.
