Proxy Servers

In a Nutshell - CIW Course Section 3, Part B3, Chapter 7

Overview of Proxy Servers

Proxy servers can be considered as a barricade around a private network. It allows clients in the private network to communicate with an external network, usually the Internet, without being physically connected to the external network. Any requests made by the client, for data from the external network, are passed to the Proxy Server, which relays the requests on to the external network. The external network only ever sees the IP address of the Proxy server, so all internal IPs are hidden.

A proxy server can enforce security, increase bandwidth efficiency, improve logging and reduce costs.

Installing EasyProxy Server

Available for free download from IT Quality. There is a link to FreeDownloads Center, but it didn't work. EasyProxy works with Novell GroupWise and as I don't have Novell installed on any machine I could not evaluate this product nor could I obtain any screenshots.

The course notes are fairly brief and take you through selecting the adapter (NIC) to be used and the HTTP port number. It then takes you through defining a log file to be used and setting the CPU priority level.

Without being able to test it, I failed to understand how a proxy would work when defining only one network card.

Configuring AnalogX Proxy Server

Available for free download from FreeDownloads Center. After installation click Start | Programs | AnalogX | Proxy | Proxy to run the program. It will display a warning dialog about running proxy in an open state. Click OK. At this point, nothing appears, except an icon in the system tray. Right-click the icon and select "Configure". The following screen appears:

Logging and protocol settings are simple toggled values. Clicking "Disabled" under Logging will enable Logging. Similarly, clicking the "Off" button below one of the protocols will enable that protocol as seen in the next image.

I have not tested the functionality of this product, but it looks to be a very light-weight proxy server. I use Microsoft Internet Security and Acceleration (ISA) Server which is a serious commercial product and has far greater functionality than AnalogX.

Configuring Apache Proxy Server

Apache Server can be configured to act as a Web proxy server. All settings pertinent to this functionality are contained within the httpd.conf file. The required lines exist in the file but will be commented out. To enable proxy server it is just a question of identifying the lines and removing the comment symbol from the start of the line.

The required lines are:

<IfModule mod_proxy.c>

<Directory proxy:*>
Order deny.allow
Deny from all
Allow from .your_domain.com
</Directory>

LoadModule proxy_module modules/libproxy.so

AddModule mod_proxy.c

ProxyVia Full

CacheRoot */var/cache/httpd*