Posted 19 April 2000 - 04:33 PM
IPv4 multicasting occurs on class D addresses (220.127.116.11 - 240.0.0.0). In order to perform multicasting over IP you need to bind a datagram socket to a multicast address on a specified socket. The address should be specific to the application, the socket should be specific to the session. Then, provided that all clients are on multicast capable networks, all transmissions directed to that IP/socket combo can be recvfrom()''d by all clients. Of course, a great many networks are still not multi-cast routing capable. A single send is still going to a single IP address (the multicast address), but multiple computers are receiving the packets.