The technique of using multiple network interface cards (NICs) in a single server or configuring a single NIC with multiple IP addresses. On a TCP/IP network, a multihomed machine has a separate IP address assigned to each of its interfaces. Multihoming is typically used to increase bandwidth by providing connectivity to several networks simultaneously.
Multihoming is also used when a computer is connected to both a direct local area network (LAN) connection and the Internet using a dial-up networking connection. Another use of multihoming is to allow a privileged station to connect to both a low-security LAN and a restricted high-security LAN. These kinds of multihoming are supported by Microsoft Windows 98, Windows NT, and Windows 2000.
Another use for multihoming is when a machine running Windows NT Server or Windows 2000 Server is used as a router. By installing two or more NICs in a single machine running Windows NT Server or Windows 2000 Server and enabling Routing Information Protocol (RIP) on the machine, you can have the server function as a dynamic router that can exchange routing table information with other RIP-enabled routers. Or, if you do not enable RIP on the server, it can function as a static router, in which case you would manually configure the server’s routing table from the command prompt using the route command.
Graphic M-18. A multihomed server.