[TBD] Understanding multihoming

Introduction

Laymen explanation

Each network interface on an IP internetwork has a separate IP address. In a classical network, each regular computer, usually called a host, attaches to the network in exactly only one place, so it will have only one IP address. This is what most of us are familiar with when using an IP network (and is also why most people use the term “host” when they really mean “network interface”.)

If a device has more than one interface to the internetwork, it will have more than one IP address. For example, suppose that laptop has wifi as well as wired connection(and so it is multi-homed device). He is using wired network initially. Once he moves laptop to another place(for meeting someone), he will use wi-fi network.

Technical explanation

In below diagram,internetwork consists of two LANs, A (shown in purple) and B (shown in blue). LAN A has a multihomed workstation, shown with two IP network interface “circles”. The two LANs are connected together through a multihomed, shared server, that has been configured to route traffic between them. Note that this server also handles all traffic passing between LAN B and the Internet (since the Internet connection is in LAN A only.

Reference

http://www.tcpipguide.com/free/t_NumberofIPAddressesandMultihoming.htm