No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


Configuration Guide - IP Multicast

CloudEngine 12800 and 12800E V200R005C10

This document describes the configurations of IP multicast, including IP multicast basics, IGMP, MLD, PIM (IPv4), PIM (IPv6), MSDP, multicast VPN, multicast route management (IPv4), multicast route management (IPv6), IGMP snooping, MLD snooping, static multicast MAC address, multicast VLAN, multicast network management.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Overview of MLD Snooping

Overview of MLD Snooping


Multicast Listener Discovery (MLD) snooping is an IPv6 Layer 2 multicast protocol. The protocol listens to multicast protocol packets exchanged between a Layer 3 multicast device and user hosts to maintain outbound interfaces of multicast packets, based on which it manages and controls multicast packet forwarding at the data link layer.


Similar to an IPv4 multicast network, an IPv6 multicast network also contains Layer 2 switching devices. Multicast packets must pass through these Layer 2 switching devices, especially when they are transmitted in a LAN. In Figure 11-1, a Layer 2 switch is located between multicast users (HostA and HostB) and the Layer 3 multicast device (router).

Figure 11-1 MLD snooping network diagram

After the switch receives multicast data packets from the router, the switch forwards the packets the hosts. The destination address of these multicast data packets is a multicast group address, and the Layer 2 switch cannot learn MAC address entries of such addresses. Therefore, the switch broadcasts the multicast data packets to all the interfaces in the same broadcast domain. All hosts in the broadcast domain will receive the multicast data packets, regardless of whether they are members of the multicast group. This wastes network bandwidth and threatens network security.

MLD snooping solves the preceding problem. With MLD snooping configured, the Layer 2 switch listens to and analyzes MLD packets exchanged between multicast users and the upstream router, and creates Layer 2 multicast forwarding entries based on MLD packet information. Multicast data packets are then forwarded based on the Layer 2 multicast forwarding entries, instead of being broadcast in the Layer 2 network.

Updated: 2019-04-20

Document ID: EDOC1100074724

Views: 37701

Downloads: 13

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Previous Next