IP Programming Basics

Overview

The Internet Protocol (IP) is at the core of network programming. IP is the vehicle that transports data between systems, whether within a local area network (LAN) environment or a wide area network (WAN) environment. Though there are other network protocols available to the Windows network programmer, IP provides the most robust technique for sending data between network devices, especially if they are located across the Internet.

Programming using IP is often a complicated process. There are many factors to consider concerning how data is sent on the network: the number of client and server devices, the type of network, network congestion, and error conditions on the network. Because all these elements affect the transportation of your data from one device to another, understanding their impact is crucial to your success in network programming. Often what you think is happening in your programs is not happening on the network. This chapter describes a method of watching IP traffic on the network to help you debug your network programs.

This chapter also examines the parts of IP communications necessary to your understanding of network communications, along with the inner workings of the two most popular protocols that use IP: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). Finally, one of the most confusing network issues is IP network addressing. This chapter finishes up with a helpful look at Microsoft Windows systems’ handling of IP addresses, and how you can programmatically determine the IP address configuration of the system on which your program is running.