Monilähetysosoitteita

Monilähetysosoitteita, often translated as multicast addresses, are special IP addresses used in computer networking to identify a group of devices that wish to receive a particular stream of data. Instead of sending data to each individual device on a network, a single transmission to a multicast address is delivered to all subscribed members of that group simultaneously. This is highly efficient for applications where the same data needs to reach multiple recipients, such as video streaming, online gaming, or software updates.

The Internet Protocol (IP) supports both IPv4 and IPv6, and both versions have their own ranges of multicast addresses. In IPv4, multicast addresses fall within the Class D range, specifically from 224.0.0.0 to 239.255.255.255. Within this range, certain addresses are reserved for specific purposes, like link-local multicast addresses (224.0.0.0/24) which are only used on the local network segment. IPv6 utilizes a different address space for multicast, typically starting with the prefix FF00::/8.

To receive multicast traffic, a device must explicitly join a multicast group using protocols like the Internet Group Management Protocol (IGMP) in IPv4 or Multicast Listener Discovery (MLD) in IPv6. Routers on the network are responsible for forwarding multicast traffic only to network segments where at least one member of the target group is present, further optimizing network bandwidth. This mechanism is fundamental for efficient one-to-many communication across IP networks.