CHAPTER 36

Proxying, Reverse Proxying, and Virtual

Private Networks (VPNs)

IN THIS CHAPTER

What    Is  a   Proxy   Server?

Installing  Squid

Configuring Clients

Access  Control Lists

Specifying  Client  IP  Addresses

Sample  Configurations

Virtual Private Networks    (VPNs)

References

You can never have enough of two things in this world: time and bandwidth.

Ubuntu comes with a proxy server, Squid, that enables you to cache web
traffic on your server so that websites load faster and users consume less
bandwidth. Sometimes proxy servers are recommended for security and
privacy, but a virtual private network (VPN) is an even better option if
security and privacy are your main concerns. The last section of this chapter
is about VPNs. Both proxy servers and VPNs have the interesting side effect
that when they are in use, everything that your computer connects to—say a
website—assumes that the IP address of the proxy or VPN server is your IP
address.

What Is a Proxy Server?

A proxy server lies between client machines—the desktops in your company
—and the Internet. As clients request websites, they do not connect directly to