Unfortunately, as critical as the Internet has become to doing business, it's a wide-open gateway into your computer systems. Any weak spot in your software systems leaves you vulnerable. Without a firewall, you may as well be displaying a welcome mat, inviting hackers in to wreak whatever havoc they might.

For example, if you're an e-commerce business, a hacker might try to access your customers' credit card numbers or email addresses.

And though it's hard to imagine why, some bored computer experts infiltrate systems not for personal gain, but for the simple joy of being where they shouldn't be.

Plus, don't overlook unethical insiders. Disgruntled employees aren't always above using private company data for unsavory purposes.

What is a firewall?

A firewall prevents unauthorized access to your private network. Essentially, it screens all information coming into or going out of your private network to make sure it meets certain select security criteria predetermined by you.

Not only can a firewall help prevent outsiders from accessing your data, it can also guard against unauthorized access within your own company walls.

How does a firewall work?

There are two kinds of firewalls: software-based and hardware-based. Software-based firewalls consist of software that typically runs on a standard server (a high-end computer dedicated to performing one particular task). Also available are hardware Internet devices that help connect your computers to a LAN (local area network) while also providing Internet security functions like firewalls.

Both methods allow you to determine what types of information can both enter and exit your network. And firewalls aren't just roadblocks; they are also security guards, and can alert you when potentially destructive data is trying to enter your network, so you can better attempt to pinpoint a culprit and motive.

Who needs a firewall?

You should set up firewalls if your business uses an Internet connection to do any of the following: send and receive email, FTP (to transfer files), telnet, browse the Web, participate in news groups, access computers remotely, video conference, use Internet telephony, and instant message.

How do I get a firewall? For businesses of less than 10 employees that aren't dealing with highly sensitive data, straight-out-of-the-box software solutions ($40 to $100) are your easiest and more affordable option. They can be installed right onto your desktop computers.

For more than 10 employees, or to protect a more sensitive operation, you'll want an enterprise level software solution. This will require using a server -- a high-end computer dedicated to performing one particular task. Annual costs for a commercial-grade firewall can easily run from $5000 to $30,000 and then some, including set-up fees, maintenance charges and ongoing software updates. And for this level of security, you'll want the aid of a full-time IT manager to maintain proper performance.

If you're in the process of setting up a network in your home or office, consider a hardware Internet device that helps connect your computers to a local area network (LAN) while also providing Internet security functions like firewalls. These types of device are great solutions for small business supporting up to 100 employees. Prices for these devices range from as low as $150 to as high as $700 depending on the number of users it supports and its features.

Here's something to keep in mind as you explore your firewall options. Though most solutions will be more than adequate for the needs of your average business, no security solution is foolproof. If you're running a particularly sensitive operation, a security consultant or one of your own IT staff may advise you to double your efforts by incorporating both a hardware and software solution.

See also:
   IT Consulting Buyer's Guide
   Server Buyer's Guide
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