Unicast IPv4 Routing Technical Reference

Unicast IPv4 Routing Technical Reference

This technical reference describes unicast Internet Protocol version 4 (IPv4) routing and explains how it works on an internetwork using servers, including routers, that run the Microsoft Windows Server 2003 operating system. IPv4 (often referred to as IP) is a major component of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite, which is the standard networking protocol used in most networking environments today as well as on the Internet. A TCP/IP-based internetwork, typically, is called an IP internetwork, although the IP network protocol is only a part of TCP/IP.

IP is the routable network protocol that makes communication possible across IP internetworks. Unicast IP routing refers to the process of transmitting IP packets from a single node (a host or a router) to a single node on an IP internetwork. Although, as the name Internet Protocol indicates, IP packet transmission was originally intended for traffic over the Internet, the transmission of IP packets is now also the primary type of traffic used on most intranets.

The information provided here is relevant to the IP unicast routing that occurs on any Windows-based network, including networks that use hardware routers, software-based routers such as those that use the Windows Server 2003 Routing and Remote Access service, or a combination of hardware and software routers. Included is a description of the multiple features of the Routing and Remote Access service that support unicast IP routing.

In addition to supporting IP routing, Windows Server 2003 also supports AppleTalk routing. The Windows Server 2003 family no longer supports Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) routing. Microsoft Windows 2000 Server supports unicast routing for IP, AppleTalk, and IPX networks.

Although IPv4 will likely be replaced in the future by the next generation of IP, IP version 6 (IPv6), at present most unicast IP routing takes place over IPv4 networks. Windows Server 2003 supports both IPv4 and IPv6. For more information about Windows Server 2003 support for IPv6, including support for static routing in an IPv6 environment, see “IPv6 Technical Reference.”

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