Cisco Cisco Web Security Appliance S670 User Guide

Authentication

Configure authentication parameters, such as the number of outstanding 
concurrent Basic or NTLMSSP authentication requests to be authenticated by 
the authentication server and whether or not to log the username that appears in 
the request URI. You can also use the 

authentication

 subcommand to enable 

the user acknowledgment page. For more information about the user 
acknowledgment page, see 

.

For more information, see 

Caching

Configure advanced Web Proxy caching options, such as:

Whether or not to ignore client requests to not retrieve content from the 
proxy cache

Whether or not to cache content from an untrusted server

You can configure the parameters separately by selecting “Customized Mode,” 
or you can choose from the modes shown below for a predefined set of 
parameter values. For more information, see 

.

Safe mode

This mode uses less caching. You might want to use safe 
mode if clients are encountering web servers sending error 
responses with Last-Modified headers (so they get 
cached), and these are transient whereby you do not want 
to cache the error responses. Or, you might want to use safe 
mode if some web servers are not responding properly to 
If-Modified-Since queries, and caching objects when no 
cache lifetime is specified is causing incorrect cache hits.

Provides most strict adherence to the RFC with respect to 
caching, performing less caching than the other modes.

Optimized mode

This mode uses moderate caching. This is the default 
mode. Compared to safe mode, in optimized mode the Web 
Proxy caches objects when no caching time is specified 
when a Last-Modified header is present. The Web Proxy 
caches negative responses.

Provides less strict adherence to the RFC with respect to 
caching than Safe mode, but more than Aggressive. 
Performs more caching than Safe mode and less than 
Aggressive mode.

Aggressive mode

This mode uses aggressive caching. Compared to 
optimized mode, in aggressive mode the Web Proxy caches 
authenticated content, ETag mismatches, and content 
without a Last-Modified header. The Web Proxy ignores 
the no-cache parameter.

Provides least strict adherence to the RFC with respect to 
caching. Performs the most caching of the modes.

Customized mode

This mode allows you to configure each parameter 
individually.