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 Book is Here... and Now On Sale!

Get The TCP/IP Guide for your own computer.
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP World Wide Web (WWW, "The Web") and the Hypertext Transfer Protocol (HTTP)
                     9  TCP/IP Hypertext Transfer Protocol (HTTP)

Previous Topic/Section
HTTP Status Code Format, Status Codes and Reason Phrases
Previous Page
Pages in Current Topic/Section
1
Next Page
HTTP General Headers
Next Topic/Section

HTTP Message Headers

HTTP communication takes place through the relatively simple exchange of request and response messages. There are only a small number of methods (commands) supported by the protocol, which might give one the impression that the protocol is quite limited. Looks can be deceiving, however. Much of the functionality in HTTP is actually implemented in the form of message headers, which convey important details between clients and servers.

Some headers can appear in only HTTP requests, some in only HTTP responses, and some in either type of message. Since they are so important, there are literally dozens of them, and many apply to both requests and responses, I decided to describe them in detail in a separate section rather than try to summarize them too much in the course of describing the message formats

In this section I provide a description of each of the many headers used in HTTP request and response messages. The section contains four topics, each of which covers one of the four basic types of HTTP headers: general headers, request headers, response headers and entity headers.

Background Information: I assume here that you have already read the preceding section describing HTTP message formats.


Note: For the purpose of determining how Web caches treat HTTP messages, HTTP headers are categorized as either end-to-end or hop-by-hop headers. The former are meaningful only to the ultimate recipient of a message, while the latter are relevant to each device in the chain of devices (such as proxies) connecting a client and server. To avoid unnecessary complication I have not categorized the headers in this section using these categories; see the topic on caching for more information. In the descriptions of the individual headers, I indicate which headers are hop-by-hop; all others are end-to-end.


Quick navigation to subsections and regular topics in this section



Previous Topic/Section
HTTP Status Code Format, Status Codes and Reason Phrases
Previous Page
Pages in Current Topic/Section
1
Next Page
HTTP General Headers
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.