SysAdmin: A Linux Internet Gateway

“Back in the February 2000 issue, I covered the idea of setting
up an intra-office email server using Linux. Designed to work as a
standalone email solution for a small or home office, the logical
next step is to branch this machine to an Internet connection and
bring the office online. Online means many things to many people,
but email is still arguably the most powerful reason to provide
company-wide Internet access. Consequently, your setup will no
doubt require providing email as well as Web-browsing capabilities.
You can define who gets access and to what.”

“While I will review some of the topics covered earlier, I’ll
assume that you can refer to the February 2000 issue for how to set
up the original mail server. This beginning-level article will
show how to configure a Linux system to provide Internet access.
I’ll also show how to accomplish this for a minimum of cost, with
one company sharing a single phone line, a single modem, and a
single dial-up account to an ISP.
This setup demonstrates the
magic of IP forwarding and masquerading – a technique that makes
all hosts in a network appear as though they are coming from the
single Internet-connected Linux server.”

“The setup I will present here is actually comprised of two main
components. One is the technical side – the nuts and bolts of using
Linux to create this simple, powerful server. The second is more
marketing related. I will start with the second component – the
search for a friendly ISP begins.”