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!

Read offline with no ads or diagram watermarks!
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)
                          9  HTTP Messages, Message Formats, Methods and Status Codes

Previous Topic/Section
HTTP Generic Message Format
Previous Page
Pages in Current Topic/Section
12
3
Next Page
HTTP Response Message Format
Next Topic/Section

HTTP Request Message Format
(Page 3 of 3)

Headers

After the request line come any of the headers that the client wants to include in the message; it is in these headers that details are provided to the server about the request. The headers all use the same structure, but are organized into categories based on the functions they serve, and whether they are specific to one kind of message or not:

  • General Headers: General headers refer mainly to the message itself, as opposed to its contents, and are used to control its processing or provide the recipient with extra information. They are not particular to either request or response messages, so they can appear in either. They are likewise not specifically relevant to any entity the message may be carrying.

  • Request Headers: These headers convey to the server more details about the nature of the client's request, and give the client more control over how the request is handled. For example, special request headers can be used by the client to specify a conditional request—one that is only filled if certain criteria are met. Others can tell the server which formats or encodings the client is able to process in a response message.

  • Entity Headers: These are headers that describe the entity contained in the body of the request, if any.

Request headers are obviously used only in request messages, but both general headers and entity headers can appear in either a request or a response message. Since there are so many headers and most are not particular to one message type, they are described in detail in their own complete section.

Key Concept: HTTP requests are the means by which HTTP clients ask servers to take a particular type of action, such as sending a file or processing user input. Each request message begins with a request line, which contains three critical pieces of information: the method (type of action) the client is requesting; the URI of the resource upon which the client wishes the action to be performed, and the version of HTTP that the client is using. After the request line come a set of message headers related to the request, followed by a blank line and then optionally, the message body of the request.



Previous Topic/Section
HTTP Generic Message Format
Previous Page
Pages in Current Topic/Section
12
3
Next Page
HTTP Response Message Format
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.