Internet firewalls can prevent browsing and file sharing (298804)

SYMPTOMS

After you enable an Internet firewall, you may not be able to search, or "browse," for other computers on your home or office network, and you may not be able to share files with other computers on your home or office network. For example, when you enable the Internet Connection Firewall (ICF) feature in Microsoft Windows XP, you find that you cannot browse your network by using My Network Places. Also, if you use the net view \\computername command to view shares on a computer on your home or office network, you may receive the following error message:

System error 6118 has occurred. The list of servers for this workgroup is not currently available.

RESOLUTION

To resolve this behavior, use a firewall only for network connections that you use to connect directly to the Internet. For example, use a firewall on a single computer that is connected to the Internet directly through a cable modem, a DSL modem, or a dial-up modem. If you use the same network connection to connect to both the Internet and a home or office network, use a router or firewall that prevents Internet computers from connecting to the shared resources on the home or office computers.

Do not use a firewall on network connections that you use to connect to your home or office network unless the firewall can be configured to open ports only for your home or office network. If you connect to the Internet by using your home or office network, a firewall can be used only on the computer or the other device, such as a router, that provides the connection to the Internet. For example, if you connect to the Internet through a network that you manage, and that network uses connection sharing to provide Internet access to multiple computers, you can install or enable a firewall only on the shared Internet connection. If you connect to the Internet through a network that you do not manage, verify that your network administrator is using a firewall.

MORE INFORMATION

A firewall is software or hardware that creates a protective barrier between your computer and potentially damaging content on the Internet. It helps guard your computer against malicious users and against many computer viruses and worms.

For additional information about third-party firewall products, visit the following Microsoft Web site:

http://www.microsoft.com/security/articles/firewall.asp

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

308127 How to manually open ports in Internet Connection Firewall in Windows XP

Important If you set up a firewall to help protect computer ports that are connected to the Internet, we do not recommend that you open these ports because they can be exposed to other computers on the Internet. Additionally, specific computers cannot be granted access to the open ports.

The following ports are associated with file sharing and server message block (SMB) communications:

Microsoft file sharing SMB: User Datagram Protocol (UDP) ports from 135 through 139 and Transmission Control Protocol (TCP) ports from 135 through 139.
Direct-hosted SMB traffic without a network basic input/output system (NetBIOS): port 445 (TCP and UPD).

Technical support for Windows x64 editions

Your hardware manufacturer provides technical support and assistance for Microsoft Windows x64 editions. Your hardware manufacturer provides support because a Windows x64 edition was included with your hardware. Your hardware manufacturer might have customized the Windows x64 edition installation with unique components. Unique components might include specific device drivers or might include optional settings to maximize the performance of the hardware. Microsoft will provide reasonable-effort assistance if you need technical help with your Windows x64 edition. However, you might have to contact your manufacturer directly. Your manufacturer is best qualified to support the software that your manufacturer installed on the hardware.

For product information about Microsoft Windows XP Professional x64 Edition, visit the following Microsoft Web site:

http://www.microsoft.com/windowsxp/64bit/default.mspx

For product information about Microsoft Windows Server 2003 x64 editions, visit the following Microsoft Web site:

http://www.microsoft.com/windowsserver2003/64bit/x64/default.mspx

For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:

283673 How to turn on or turn off the firewall in Windows XP

324731 Support WebCast: Microsoft Windows XP: Internet Connection Firewall

For additional information about home and small office networking with Windows XP, visit the following Microsoft Web site:

http://www.microsoft.com/windowsxp/using/networking/default.mspx

For additional information about how to use Internet Connection Firewall, visit the following Microsoft Web site:

http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/icf.mspx