Tunneling Data
Network tunneling can be helpful and even necessary, but it can also be used to circumvent security policies. Here’s a survey of the best tunneling tools available and a list of techniques that may help you detect active tunnels.
Wednesday, June 15th, 2005
Nowadays, firewalls, intrusion detections systems (IDS), and other security devices are a necessary part of any corporate network infrastructure. Such systems have even become commonplace in many homes.
But even with security gear installed, don’t let your guard down. Security requires vigilance, multiple layers of defense, and a heavy dose of paranoia. It also takes knowledge of what the “bad” guys — or in many cases, employees who may not necessarily have bad intentions — will do to try to subvert the measures you have put into place. You’d be surprised just how crafty some people in your organization may become when trying to circumvent a firewall rule or corporate policy they don’t think is fair.
In this month’s “Tech Support,” let’s look at a couple of applications that let you
tunnel data in ways that may surprise you and catch your firewall off guard. Let’s look too at an application that may help you track down data tunnels (but be aware that a well hidden tunnel can be nearly impossible to find). As is often the case with security tools, these applications can be used for nefarious purposes, so use your best judgment. And while this article doesn’t cover
netcat (
http://netcat.sourceforge.net/), the swiss army knife of all network tunneling apps, it’s a tool that every network administrator should be aware of.[ You can find more information about netcat at
http://www.linux-mag.com/2003-10/diy_01.html.]
