The following table lists the HTTP caching directives that the appliance follows.

Directive source

Caching directives

 

 

administration

Don’t cache objects with URL addresses containing ?,

options

;, /cgi or end in .asp.

 

Don’t cache objects served in response to the Cookie:

 

header.

 

Set never-cache rules from the command-line

 

interface. Refer to Configuring caching rules‚ on

 

page 79.

 

 

client

Don’t cache objects with the following request headers.

 

You can override some of these directives using

 

administration options.

 

Cache-Control: no-store header

 

Cookie: header

 

Authorization: header

 

 

Web server

Don’t cache objects with the following response headers.

 

You can override some of these directives using

 

administration options.

 

Cache-Control: no-store

 

www-Authenticate: header

 

Set-Cookie: header

 

Cache-Control: no-cache header

 

Pragma: no-cache header

 

Expires: header with value of 0 (zero) or a past date

 

 

Transparent proxy caching

In nontransparent proxy caching, client browsers must be configured to send Web requests to the Intel NetStructure Cache Appliance proxy. Many sites have no direct control over user browser settings, making it necessary for site administrators to tell users to configure their browsers to direct requests to the proxy.

Transparency solves this problem. The transparency option enables the appliance to respond to Internet requests without requiring users to reconfigure their browser settings. It does this by redirecting the traffic flow into the cache after it has been intercepted by an L4 switch or router.

This section provides the following:

An overview of how the appliance serves requests transparently. See Serving requests transparently‚ on page 121.

A discussion of interception strategies supported by the Intel NetWorking Cache Appliance. See Interception strategies‚ on page 121.

120Intel NetStructure Cache Appliance Administrator’s Guide

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Intel 1520 manual Transparent proxy caching, Directive source Caching directives