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The risk of Internet intrusion is higher if you have an always-on broadband Internet connection, such as DSL or cable. Internet intrusion can come from down the block or halfway around the world.
After you've set up a firewall for your home network, you should perform routine tasks to maintain the firewall. To update the firewall, right-click the firewall program's icon in the Windows system tray and choose Update Components. Follow the on-screen instructions to download and install updates.
Halting network traffic
If your computer has a lot of hard drive activity but no programs are running, and your Internet connection is flowing a lot of data but no one is online, activate the Halt Internet Traffic command. If the hard drive activity or connection activity suddenly stops, then it is likely that your computer was being attacked.
Use these steps to halt network traffic:
1. Right-click the Windows system tray icon for your Internet security program.
2. In the context menu, choose Halt Internet Traffic. Traffic between your computer and the Internet should be disabled.
3. Run a complete virus and Internet security scan of your computer to identify and neutralize potential threats on your computer.
4. Choose Halt Internet Traffic again to re-enable Internet traffic. You can also disable and enable traffic from directly within your security program, as shown in Figure 1.
Figure 1: Reactivate your Internet connection when you believe it's safe.
 | The Halt Internet Traffic command only works on the computer on which it is installed. Halting Internet traffic on one computer won't prevent other computers on your network from connecting with the Internet. |
Reviewing the firewall logs
Most activities listed in the firewall logs are harmless network functions. However, if you are having network connection difficulties, or if you have been victimized by an attack from outside your network, these logs can help you identify and troubleshoot those problems.
Use the following steps to review the firewall logs:
1. Open the control panel for your firewall program.
2. Locate the logging or event logs section of the control panel and open it.
3. Open a log:
• Third-Party Firewalls: If the program maintains several different kinds of logs, choose the Firewall or Personal Firewall logs and click View Logs.
• Windows Firewall: Use My Computer or Windows Explorer to open the folder C:\WINDOWS and then double-click the file pfirewall.log.
4. Review the firewall logs (see Figure 2). If you are using the Windows Firewall, the file pfirewall.log opens in a text editor.
Figure 2: Review your firewall logs.
 | When you review the firewall logs, look for entries that come from source IP addresses outside of your network. Sources inside your own network usually start with 192.168, as shown in Figure 2. |
Adding programs to an exception list
Follow these steps to add programs to an exception list:
1. Open the control panel for your firewall program.
2. Open the firewall controls. If you see an exception list area, open it. Otherwise, open the personal firewall settings, select your security profile, and click Edit.
3. Open the Exception List tab or controls.
4. Click Add, and then type a descriptive name for the exception.
5. Click Browse and locate the program file for the program for which you are creating an exception.
| Program files are usually located in the folder C:\PROGRAM FILES and most have the .EXE file extension. |
6. Choose to which target group the exception applies.
7. Choose whether you want the exception rule to allow traffic, deny traffic, or warn you when traffic is about to occur.
Choose Deny if you want to block a program from using the network.
8. Click OK to save your new exception rule.
Blocking ping commands
The ping command is used simply to determine if a computer's IP address is valid. Hackers sometimes use the ping command to identify valid, active IP addresses to attack. By blocking ping commands, you make your network less visible to hackers.
Follow these steps to block ping commands:
1. Log in to your router's control panel.
2. Locate the controls for blocking WAN ping commands.
3. Enable WAN ping blocking, as shown.
4. Click OK or Apply to save your changes.
| If you connect to the Internet through a dial-up connection, blocking ping commands is less important because your ISP probably gives you a different IP address every time you connect. |
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