Linux Journal: Encrypted Tunnels with FreeS/WAN’s x509 Patch

“In countries where a private or semi-public WAN is something
not every company can afford, the Internet is the only option
available to connect all of those remote offices. The obvious
problems are this is a public network and, in most cases, we don’t
get a static IP address. We know that sending data through the
Internet is like talking to somebody in an elevator–everybody just
can’t help hearing what you’re saying. So, not encrypting the data
is not an option.

“Many types of tunnels can be used and VPNs can be put together
in many ways, but the IPsec implementation of Linux (FreeS/WAN) is
by far the most secure and compatible way to do it. In this
article, I explain how to establish LAN-to-LAN tunnels using the
x509 patch and only one static IP address. I also tell you two ways
to get around the four tunnel inconvenience…”

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