Configure header options

When requesting documents, web clients send headers that provide additional information about the browser or the request. Headers are automatically generated when a request is sent.

Caching Proxy allows several options for customizing header information to keep it hidden from the destination server. Although substituting a more generic header for the actual header has the advantage of increasing client anonymity, it has the disadvantage of disabling header-based page customization that is written into some web pages.

Headers typically use this form:
User-Agent: Mozilla 2.02/OS2 
Client-IP: 45.37.192.3 
Referer: http://www.bigcompany.com/WebTrafficExpress/main.html
This header includes the following fields:
  • User-Agent: provides information about the browser and operating system.
  • Client-IP: provides the IP address of the client requesting the URL.
  • Referer: provides the destination server with the URL of the referring link to this page.

Most headers can be blocked by the appropriate proxy configuration settings. However, some header fields are required by origin servers, so blocking them can cause web pages to be displayed incorrectly (For example, in certain cases blocking the host header field can cause users to see the wrong web page). For more information on header fields, refer to the HTTP Version 1.1 specification.

Associated directives

Configuration and Administration forms

You can use two Configuration and Administration forms to specify header options:
  • Select Proxy Configuration –> Privacy Settings. In the Privacy Settings form, set the following:
    • Forward client's IP address to destination server

      Check this box if you want the requesting client's IP address to be forwarded to the destination (content) server. If you do not check this box, the destination server receives the IP address of the proxy server. Leaving this box unchecked increases the clients' anonymity while browsing the web.

    • User-agent string
      Type the string to send in the header to the destination server to replace the type of browser and operating system that a client is using. For example: specifying Caching Proxy 4.0 replaces Mozilla 2.02/OS2 in the following header:
      Content-Type:MIME  
      User-Agent: Mozilla 2.02/OS2  
      Referer: http://www.ics.raleigh.ibm.com/WebTrafficExpress/main.html  
      Pragma:no-cache
    • From:

      Type the email address that the destination server reads when it parses the From header. You might want to specify the email address of the proxy administrator because the administrator is the person who needs to receive reports of any problems.

    • Click Submit to make the changes to the configuration file.
  • Select Proxy Configuration –> Proxy Header Filtering. Use this form to list HTTP headers to block:
    1. Click Add or Remove, and indicate an index position for the blocked header.
    2. Type the client HTTP header to block. (Refer to the HTTP 1.1 specification for a complete list and explanation of headers.)
    3. Click Submit to make the changes to the configuration file.

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Timestamp icon Last updated: March 23, 2018 0:18
File name: headers.html