IPv4 Multicasting Technical Reference

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

IPv4 Multicasting Technical Reference

Internet Protocol (IP) multicasting is the delivery of a single IP datagram to a group of hosts, regardless of their location, on a TCP/IP-based network. Of the three delivery methods supported by IP — multicasting, unicasting, and broadcasting — multicasting is the most practical method for point-to-multipoint data transmission, because unicasting requires multiple copies of datagrams and broadcasting does not work across routers.

Multicasting in an IP version 4 (IPv4) network is different from multicasting in an IP version 6 (IPv6) network. This document describes multicasting with IPv4. IPv4 is frequently referred to as IP and that convention is used in this document. For information about multicasting with IPv6, see “IPv6 Technical Reference.”

Although Windows Server 2003 does not provide any multicast routing protocols, the Routing and Remote Access service provides a platform that supports these multicast routing protocols. In addition, you can configure Routing and Remote Access as a multicast forwarder for limited network configurations.

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