Internet security is almost an oxymoron, as a computer connected to the Internet is the least secure of machines. However, many organizations have found ways to protect the internal network from Internet attacks as well as ensure that employees are not violating the Internet use policy. One of those solutions is a proxy server, which sits between the client computer and the Internet, intercepting packets and ensuring a higher level of security for the network than is otherwise possible. Squid is the de facto proxy standard for Ubuntu Linux installations.
Install Squid with the following command at the Linux command prompt:
sudo apt-get install squid
Linux will install the software and update the proper libraries.
Navigate to /etc/squid/ with the following command:
Edit the Squid configuration file with your favorite text editor, and add the following lines:
http_access allow local_net acl local_net src 10.10.0.0/255.255.0.0
In the second line, 10.10.0.0 is your network’s address. You can add other networks with similar acl lines to expand the proxy’s control.
Save the file, exit the editor and restart Squid. You are now ready to configure your browser to use the proxy server.
Click "Tools," "Options," "Advanced," "Network" and "Settings" in Firefox, which is the normal Ubuntu Linux browser. Select "Manual Proxy Configuration," enter the IP address of your proxy server, enter port 3128 in the Port field and then click "OK." While you can configure your proxy server for more functionality, your basic secure proxy server is now active.
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