How to set up a proxy server

Block websites and protect your network from malware

Corporate networks always have proxy servers, while on home networks they're often an overlooked form of defence. But maybe they shouldn't be.

A local proxy server can help to improve the throughput of your broadband connection, restore order to a troubled network and add another line of defence against malware infections.

What are proxies?

'Proxy' means substitute. To the computers on the local network, a proxy server is a substitute for connecting directly to the web. There are several different types of proxy server. For example, a web proxy server keeps copies of recently accessed web pages on your hard disk.

When you access a page, the proxy serves the cached version if it's up to date. This is faster than downloading static files from the site. All internal computers must use the local web proxy server for it to be effective.

In the settings for your web browser, there's a page to point it at a proxy server rather than the network's default gateway. This gateway is usually a router or the computer attached to your broadband modem. Some proxy servers also block content, especially on corporate networks.

You may be tempted to disable the proxy settings in your browser to view sites your boss would rather you didn't during work hours. However, to ensure that everyone on the network uses the proxy to access the internet, system administrators block all access to the internet at their firewall, except traffic coming from or going to the proxy. So to access anything outside the local network, you must use the proxy.

Forcing everyone to use the proxy gives system administrators great control over what their users can access. The same principle can be used at home by parents and those simply keen to bolster security.

If you find unexpected access attempts in a firewall's log file from inside a proxy-protected network, they're probably coming from malware that doesn't know how to test for a local proxy and has tried to go directly online.

Installing FreeProxy

FreeProxy (or FreeProxy Internet Suite) is a free Windows-based proxy server that can provide web caching for faster access and is able to block banned web domains. It works on Windows 7 and should ideally run on its own computer. The app is available for free from here.

Once downloaded, unzip the file and double-click on the setup application. When the installation wizard appears, click 'Next' to accept the licence agreement, the default the destination folder and Start menu folder, then click 'Install'. When the release notes pop up, click 'Next', then 'Finish'. Click Start and select 'FreeProxy Control Centre'.

Let's begin by configuring and testing FreeProxy for basic use. Open a command line and enter ipconfig. Press [Enter] and one or more blocks of information will appear.

Find the one about the server's Ethernet connection (usually the first one that appears) and note the IP addresses of the default gateway and DNS server. First, we need to stop relying on DHCP to provide IP addresses on demand and use a fixed address instead. This is so other computers on the network can find the proxy server via its address.

In Windows 7 or Vista, open the Control Panel and click 'Network and Internet | Network and Sharing Centre'. In Windows 7, click 'Change Adaptor Settings' in the left-hand pane and double-click the 'Local Area Connection'.

In Vista, click on 'Manage network connections' and double-click on the 'Local Area Connection'.

In XP's Control Panel, double-click 'Network Connections' and then doubleclick the 'Local Area Connection'. Click 'Properties' and a window will appear showing the underlying configuration. Double-click the entry in the protocol list called 'Internet Protocol Version 4 (TVP/Ipv4)'. In XP this is just called 'Internet Protocol (TCP/IP)'.