Whatever Happened to the Firewall?

Have you noticed that nobody gets excited about a firewall anymore? There was a time when the firewall was the single most important security device in your network. So what happened?

The answer is a bit of a cliché, but — the Internet has changed everything! Years ago, most firewalls did a pretty good job of controlling traffic in and out of corporate networks. That’s because application traffic was generally well behaved. E-mail would typically flow through port 25, FTP was assigned to port 20, and the whole “Web surfing” was hanging, uhhh, port 80. Everybody played by the rules that “ports + protocols = applications” and the firewall had everything under control.

Blocking a port meant blocking an application. Nice and simple. Unfortunately, the Internet has never really been nice and simple. And that is truer today than ever before. Today, the Internet often accounts for 70 percent or more of the traffic on your corporate network. And it’s not just port 80 Web surfing. Typically, 20 to 30 percent of it is encrypted SSL traffic on port 443. Even worse, there is a plethora of new Internet applications that insist on making their own rules. They wrap themselves in other protocols, sneak through ports that don’t belong to them, and bury themselves inside SSL tunnels. In short, they just don’t play fair.

All these applications carry some inherent risk to your business. And they play host to clever new threats that can slip through your firewall undetected. Meanwhile, your firewall just sits there like nothing is wrong because it’s still playing by rules that don’t exist anymore!