Installation guide

For explicit proxy deployment, individual client browsers may be manually
configured to send requests directly to the proxy. They may also be configured to
download proxy configuration instructions from a Proxy Auto-Configuration (PAC)
file. A group policy that points to a PAC file for configuration changes is a best
practice for explicit proxy deployments. Another option is the use of Web Proxy Auto-
Discovery (WPAD) to download configuration instructions from a WPAD server. See
Websense Content Gateway Online Help (Explicit Proxy Caching chapter) for a
sample PAC file and more information about how to implement these options.
Exception handling instructions can also be included in the PAC file or WPAD
instructions. For example, requests for trusted sites can be allowed to bypass the
proxy.
Disadvantages of explicit proxy deployment include a user’s ability to alter an
individual client configuration and bypass the proxy. To counter this, you can
configure the firewall to allow client traffic to proceed only through the proxy. Note
that this type of firewall blocking may result in some applications not working
properly.
You can also use a Group Policy Option (GPO) setting to prevent users from changing
proxy settings. If you cannot enforce group policy settings on client machines, this
type of configuration can be difficult to maintain for a large user base because of the
lack of centralized management.
Transparent proxy deployment
In a transparent proxy deployment, the user’s client software (typically a browser) is
unaware that it is communicating with a proxy. Users request Internet content as
usual, without any special client configuration, and the proxy serves their requests.
The Adaptive Redirection Module (ARM) component of Websense Content Gateway
processes requests from a switch or router and redirects user requests to the proxy
engine. The proxy establishes a connection with the origin server and returns
requested content to the client. ARM readdresses returned content as if it came
directly from the origin server. See Websense Content Gateway Online Help
(Transparent Proxy Caching and ARM chapter) for more information.
Note that in a transparent proxy deployment, all Internet traffic from a client goes
through the proxy (not just traffic from Web browsers), including:
 traffic tunneled over HTTP and HTTPS by remote desktop applications
 instant messaging clients
 software updaters for Windows and anti-virus applications
Note
Non-browser client applications that cannot specify a
proxy server may not work with explicit proxy
deployment.