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:
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 further information on header fields, refer to the HTTP Version 1.1 specification.
To change header options by editing the proxy configuration file, see the reference sections for the following directives:
For more information, refer to Manually editing the ibmproxy.conf file.
You can use two Configuration and Administration forms to specify header options:
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 surfing the Web.
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
Type the e-mail address that the destination server reads when it parses the "From:" header. You might want to specify the e-mail address of the proxy administrator because the administrator is the person who needs to receive reports of any problems.
For more information, refer to Using the Configuration and Administration forms.