An Introduction to FreeS/WAN, Part I

VPN tunnels for secure wireless and WAN connections, Part I of II.
Starting and Testing the Tunnel

And now the moment of truth! First on George and then on Gracie, we enter the command:

ipsec setup restart

George will read /etc/ipsec.conf, load the george-gracie tunnel definition into its connection setup database and wait for connections. Gracie will do the same thing and then bring up the tunnel. Startup messages will be logged to /var/log/messages or /var/log/secure. If on the client system the output from ipsec setup restart ends with an “IPsec SA established” message, your tunnel is up! Try pinging or otherwise connecting to hosts on the remote network; the connection should behave no differently from before when you brought the tunnel up. In fact, you may want to run tcpdump on your tunnel-bound Ethernet interface to make sure that only ESP (Encapsulating Security Payload) packets (i.e., encrypted tunnel packets and not actual Ping, FTP packets, etc.) are being sent out.

Next month we'll look at another VPN scenario or two and delve deeper into the splendors of FreeS/WAN. Hopefully this was enough to get you started down the path to secure wireless networking!

Mick Bauer (mick@visi.com) is a network security consultant for Upstream Solutions, Inc., based in Minneapolis, Minnesota. He is the author of the upcoming O'Reilly book Building Secure Servers with Linux, composer of the “Network Engineering Polka” and a proud parent (of children).

______________________

Geek Guide
The DevOps Toolbox

Tools and Technologies for Scale and Reliability
by Linux Journal Editor Bill Childers

Get your free copy today

Sponsored by IBM

Webcast
8 Signs You're Beyond Cron

Scheduling Crontabs With an Enterprise Scheduler
On Demand
Moderated by Linux Journal Contributor Mike Diehl

Sign up and watch now

Sponsored by Skybot