Please Whitelist This Site? I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :) If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads. If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK. Thanks for your understanding! Sincerely, Charles Kozierok Author and Publisher, The TCP/IP Guide

NOTE: Using software to mass-download the site degrades the server and is prohibited. If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The TCP/IP Guide

OSI Reference Model Layer Summary 1 TCP/IP Overview and History

Just as Ethernet rules the roost when it comes to LAN technologies and IEEE 802.11 is the boss of the wireless LAN world, modern internetworking is dominated by the suite known as TCP/IP. Named for two key protocols of the many that comprise it, TCP/IP has been in continual development and use for about three decades. In that time, it has evolved from an experimental technology used to hook together a handful of research computers, to the powerhouse of the largest and most complex computer network in history: the global Internet, connecting together millions of networks and end devices.

In this section I begin our magical tour through the mystical world of TCP/IP. J I begin with an overview of TCP/IP and a brief look at its very interesting history. I discuss the services provided in TCP/IP networks, and then explain the architectural model used under TCP/IP. I then provide a brief description of each of the most important TCP/IP protocols that are discussed in this Guide.

You may have noticed that this section is relatively small, even though its title seems to encompass the entire subject of this TCP/IP Guide. The reason is that this section only provides a high-level overview of TCP/IP. Most of the content of the Guide is concerned with explaining the several dozen individual protocols that comprise TCP/IP; these can be found in other sections and subsections of the Guide. For convenience, you can also find direct links to the descriptions of these protocols in the TCP/IP Protocols topic in this section.

OSI Reference Model Layer Summary 1 TCP/IP Overview and History