Blue Coat Systems Time Clock Proxy SG Manuale Utente

ProxySG Content Policy Language Guide

210

request.filter_service( )

Controls whether the request is processed by an external content filter service. The ProxySG currently 
supports Websense Enterprise Server external content filtering.

Directing the request to an external content filter service does not affect policy based on categories 
determined through an on-box vendor or CPL category definitions.

Categories determined by Websense Enterprise Server are not available to the 

category=

 condition, 

although they appear in access logs. Effectively, all policy based on the Websense determined 
categories must be implemented on the Websense server.

This property might be overridden by the deprecated 

content_filter_override(yes) 

property.

Replaces: 

content_filter_override(yes)

request.filter_service(servicename[, fail_open|fail_closed])

request.filter_service(no)

The default values are 

no

 and fail_closed.

where:

•

—A configured external content filter service that supports request modification. 

Currently only Websense Enterprise Server is supported. On upgrade, the service name 
websense

 is automatically generated. 

•

fail_open

—If 

 is unavailable, the request is processed and a response may be 

delivered, subject to other policy.

•

fail_closed

—If the 

 is unavailable, the request is denied.

•

no

—Prevents the request from being sent from the ProxySG to the external content filter service. 

•

Use  in 

<Cache>

 and 

<Proxy>

 layers.

•

Applies to FTP and HTTP transactions.

The following example directs requests to the Websense server, but allows processing to continue if 
the service in unavailable:

<proxy>

request_filter_service(websense, fail_open)

The following policy establishes a general rule that all request are processed by the external filter 
service named 

filter

. It then specifies some exceptions to this general rule in a later layer:

<proxy> ; All request are content-filtered by default

request.filter_service( filter )

<proxy> request.filter_servce( no )  ; exceptions to content-filtering