Vyatta NOS documentation

Learn how to install, configure, and operate Vyatta Network Operating System (Vyatta NOS), which helps to drive our virtual networking and physical platforms portfolio.

IP multicast

There are four types of transmission over a network:

  • Unicast—In unicast transmission, a single sender transmits a message to a single receiver (one-to-one). Unicast transmission is signaled to the network by using an IP address in the unicast range. Unicast transmission is supported in both IPv4 and IPv6.
  • Broadcast—In broadcast transmission, a sender transmits a message to all possible destinations (“all-hosts on this subnet”) and all receivers receive a copy of the message (one-to-many). In IPv4, broadcast transmission is signaled to the network by using the “broadcast address” or a directed broadcast address formed from the network prefix but using all binary 1s for the host portion of the address. Broadcast transmission is not supported in IPv6; instead, IPv6 defines the “all-nodes” multicast address.
  • Multicast—In multicast transmission, a group of receivers interested in a particular stream forms a group (one-to-many). The sender sends the message from its unicast address to the multicast group address. The network routers are responsible for propagating the message to all interested receivers. Multicast groups are identified using a special range of addresses. In IPv4, the former class D addresses compose the multicast range of addresses. In IPv6, multicast addresses are identified from the prefix FF00::/8.
  • Anycast—In anycast transmission, a message from a single sender is sent to the topologically “closest” node in a group of potential receivers (one-to-one-of-many). Anycast is used in network load balancing and in certain network protocols, such as Domain Name System (DNS).

IP multicast uses multicast transmission over the IP infrastructure, transmitting to a multicast address at the IP routing level. Networks using IP multicast deliver content to multiple users in various groups—for example, IP multicast is often used for content delivery such as streaming media and IPTV. IP multicast is described in RFC 1112, Host Extensions for IP Multicasting.


For specific information about the Internet Group Management Protocol (IGMP) and the Multicast Listener Discovery (MLD) protocol, see Ciena Vyatta Network OS IGMP and MLD Configuration Guide.

For specific information about Protocol Independent Multicast (PIM), see .

For specific information about Multicast Source Discovery Protocol (MSDP), see Ciena Vyatta Network OS MSDP Configuration Guide.