Windows Vista Security: Praxisorientierte Sicherheit für Profis

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Chapter 15: Protecting Your Computer with Windows Defender and Windows Firewall

Troubleshooting the Basic Windows Firewall

Like Window Defender, Windows Firewall runs as a service on your computer.

Because of this, you can use procedures similar to those discussed in the “Trouble-

shooting Windows Defender” section, earlier in this chapter, to troubleshoot Win-

dows Firewall. If you begin to experience problems connecting to your network or

you cannot connect to a specific computer or resource on the network, you may be

experiencing problems associated with Windows Firewall. Other telltale signs of fire-

wall problems include other computers failing to connect to your computer or the

inability to ping, Tracert, or access network resources even though you have an IP

address.

As with Windows Defender, start your troubleshooting by making sure Windows

Firewall is on. If the firewall is on and you are blocking all incoming connections, you

might want to clear this setting for your troubleshooting. Next, you should verify that

the Windows Firewall service is running through the Services node in Computer

Figure 15-13. Turning the firewall on or off

Working with the Windows Firewall

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Management. Verify that the service status is listed as Started, and make sure the

“Startup type” is set to Automatic. If the service is not listed as Started, click the Start

button to start the service. Also, verify the logon credentials using the Log On tab

associated with the service’s Properties dialog box. You should see “Local service” as

the selected account.

If the firewall still isn’t working properly, you need to verify the network location.

When you click the Windows Firewall option in the Windows Security Center, the

main firewall window shows the network location. If you are on a private or domain

network, other computers should be able to connect to you by default. If you are on

a public network, most types of connections to your computer are disabled. If the

wrong location type is listed, you can change the location type in the Network and

Sharing Center by clicking the network’s Customize link, selecting the desired loca-

tion type, clicking Next, and then clicking Finish. Don’t change the location type

without first considering the possible ramifications of doing so. If you are on a pub-

lic network and you specify that you are on a private network, you will open your

computer to attack.

Figure 15-14. Configuring firewall exceptions

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Chapter 15: Protecting Your Computer with Windows Defender and Windows Firewall

If the firewall still isn’t working properly, check the exceptions that are listed on the

Exceptions tab of the Windows Firewall Settings dialog box. By default, a private

network should have the following exceptions enabled:

• Core Networking

• File and Printer Sharing

• Network Discovery

• Remote Assistance

• Windows Peer to Peer Collaboration Foundation

You might also have exceptions for:

• Connect to a Network Projector

• Windows Media Player

• Windows Media Player Network Sharing Service

• Windows Meeting Space

If you believe the appropriate exceptions are enabled and you still have problems,

you can click the Restore Defaults button on the Advanced tab to go back to the

original post-installation Windows Firewall settings and remove any changes you

have made to these settings since installing the operating system. Keep in mind that

Figure 15-15. Selecting connections that should use the firewall