Install Firewalls and Other Safeguards to Keep Your Online Business Safe - dummies

Install Firewalls and Other Safeguards to Keep Your Online Business Safe

By Greg Holden

When you’re starting an online business, the objectives of a firewall are different than they are for personal use: You’re protecting not just your own information, but also that of your customers. You’re quite possibly relying on the firewall to protect your source of income as well as the data on your computers.

A firewall is an application or hardware device that monitors the data flowing into or out of a computer network and filters that data based on criteria the owner sets up. A firewall scans the packets of digital information that traverse the Internet, making sure the data is headed for the right destination and that it doesn’t match known characteristics of viruses or attacks.

Authorized traffic is allowed into your network. Attack attempts or viruses are either deleted automatically or cause an alert message to appear to which you must respond with a decision to block or allow the incoming or outgoing packets.

Keep out Trojan horses and other unwanted visitors

A Trojan horse is a program that enters your computer surreptitiously and then attempts to do something without your knowledge. Some folks say that such programs enter your system through a “back door” because you don’t immediately know that they’ve entered your system. Trojan horses may come in the form of an e-mail attachment with the filename extension .exe (which stands for executable).

Anyone who has a cable modem, DSL, or other direct connection to the Internet should install security software. You can try out the shareware program ZoneAlarm by Zone Labs, Inc., that provides you with basic firewall protection, though more full-featured programs like Norton Internet Security are probably more effective.

Clean out spyware

Watch out for software that “spies” on your web surfing and other activities and then reports these activities to advertisers, potentially invading your privacy. Ad-Aware isn’t a firewall, exactly, but it’s a useful program that detects and erases any advertising programs you may have downloaded from the Internet without knowing it. Such advertising programs might be running on your computer, consuming your processing resources and slowing down operations.

Some spyware programs track your activities when you surf the web; others simply report that they have been installed. Many users regard these spyware programs as invasions of privacy because they install themselves and do their reporting without your asking for it or even knowing they’re active.


Ad-Aware is a good choice; you can download a free version. You can pay for their Personal or Pro Security versions as well. Anotherfree anti-spyware tool you may want to try is called SpyBot Search & Destroy.

How to position the firewall

These days, most home networks are configured so that the computers on the network can share information as well as the same Internet connection. Whether you run a home-based business or a business in a discrete location, you almost certainly have a network of multiple computers.

A network is far more vulnerable than a single computer connected to the Internet: A network has more entry points than a single computer, and more reliance is placed on each of the operators of those computers to observe good safety practices. And if one computer on the network is attacked, others can be attacked as well.

You probably are acquainted with software firewalls, such as Norton Personal Firewall or Zone Alarm. Software firewalls protect one computer at a time. In a typical business scenario, however, multiple computers share a single Internet connection through a router that functions as a gateway. Many network administrators prefer a hardware firewall — a device that functions as a filter for traffic both entering and leaving it.

A hardware firewall may also function as a router, but it can also be separate from the router. The device is positioned at the perimeter of the network where it can protect all the company’s computers at once. One example of this type of hardware is the WatchGuard Firebox X20e, which costs $572, by WatchGuard.

Keep your firewall up to date

Firewalls work by means of attack signatures (or definitions), which are sets of data that identify a connection attempt as a potential attack. Some attacks are easy to stop: They’ve been attempted for years, and the amateur hackers who attempt intrusions don’t give much thought to them. The more dangerous attacks are new ones. These have signatures that emerged after you installed your firewall.

You quickly get a dose of reality and find just how serious the problem is by visiting one of the websites that keeps track of the latest attacks, such as the Distributed Intrusion Detection System or DShield.