Firewalls
Is your computer vulnerable to attack?
Test your PCs security now!
- www.symantec.com/norton/sygate/index.jsp (Sygate)
- https://grc.com/x/ne.dll?bh0bkyd2 (Gibson Research)
A firewall is a piece of hardware or software that monitors all incoming network traffic and allows in only the connections that are known and trusted. Port 80 is open so that you can browse web pages; port 1863 allows you to engage in instant messaging with friends; port 443 gives access to secure web pages used by online merchants to encrypt purchases.
You could manually grant or restrict access to each of the 65,535 ports available under the Internet Protocol. Every time you add a new program that requires Internet access, you would need to determine which port(s) it uses, and reconfigure your computer accordingly. You've likely got better ways to spend your time.
Firewall software takes on this burden for you, allowing access to the ports you need open, and closing off those you don't. It also makes your computer "invisible" on the Internet; if hackers can't find you, they will have a hard time attacking you.
More advanced firewall software also monitors outgoing traffic. This is crucial since malicious code spreads by accessing the Internet and pushing copies of itself to other computers (often those of your friends and family!). Outbound protection can keep even brand-new Trojan horses and spyware from doing their damaging work. The ultimate protection is program-level control, so that only those applications that you trust are allowed to access the Internet.
Without a firewall, your computer is operating under an "open door" policy. Bank account information. Passwords. Credit card numbers. Documents and photos that you don't want to share with the world. They are all available to anyone with bad intentions and basic computer skills. Hackers can get in, take what they want, and even leave open a "back door" so they can turn your computer into a "zombie" and use it to attack other computers.
Every minute that your computer is connected to the Internet, either through a dial-up (modem) connection or through a broadband (DSL or cable) service, it is at risk.
Windows XP Built-in Firewall (Service Pack 1 & earlier)
Update: Windows XP Service Pack 3 includes many security patches, as well as a much improved firewall. Service Pack 2 is a highly recommended download.
Although the pre-SP3 firewall is not as sophisticated as some of the other firewalls mentioned below, Windows XP (Home & Professional) has a built-in firewall. One major difference between the Windows firewall (pre-SP3) and a commercial application is that the Windows version only blocks inbound traffic, whereas a product like ZoneAlarm can be set to block both inbound and outbound traffic.
To turn on the Windows firewall, right-click your internet connection in "Network Connections" and select Properties.
Click the ADVANCED tab and place a checkmark in the Internet Connection Firewall box:
Free Personal Software Firewalls
- Sygate Personal Firewall
- ZoneAlarm
- eTrust EZ Armor Security Suite from Computer Associates (Antivirus & Firewall)
Hardware Firewalls
Although they're not free, there are a number of inexpensive hardware devices that not only have built-in firewalls, they also allow up to 253 computers to share the same broadband internet access.
These aren't the only manufacturers of this type of equipment, but they are a few of the more recommended ones. Prices for wired devices are around $100.00 or so, and they also offer wireless solutions for less than $200.00.