Configure Squid on Linux to Provide a Proxy and Network Caching

Important Files and Folders

Configuration

Change the default configuration by editing /etc/squid3/squid.conf.

Configure the devices / subnet allowed access.

	acl localnet src 192.168.1.0/24
	
	http_access allow localnet

Find the http_port tag. By default it is set to port 3128. This is the port that Squid will listen to for requests. You will also need to set this port in your browser when you configure the browser's proxy.

Since our application is multi-homed, we need to specify that squid listens on only the green zone subnet:

	http_port 192.168.1.1:3128

Running Squid

Once installed, Squid will run on boot. Squid can be restarted by:

	$ sudo service squid3 restart

If you make changes to squid.conf or later reconfigure SquidGuard, you can run a reconfigure:

	$ sudo squid -k reconfigure

You can view squid activity on an Ubuntu installation at /var/log/squid3/access.log. If configured for native format, each line will be written as shown below. Further information on the log format can be found here.

	time elapsed remotehost code/status bytes method URL rfc931 peerstatus/peerhost type

References

• Getting Squid
• Squid Architecture
• Feature: HTTPS (HTTP Secure or HTTP over SSL/TLS)
• SslBump Peek and Splice
• Squid configuration directive ssl_bump
• Intercept HTTPS CONNECT messages with SSL-Bump