Shulou(Shulou.com)05/31 Report--

It is believed that many inexperienced people are at a loss about how to find and troubleshoot the faults of the software firewall. therefore, this paper summarizes the causes and solutions of the problems. Through this article, I hope you can solve this problem.

The following article mainly tells you the actual operation scheme of software firewall fault detection and troubleshooting. Windows XP SP2 makes a problem particularly prominent. No matter what type of firewall you have or how you change your client's security settings, you can't avoid this problem. Applications that are running well may suddenly be blocked. Until you set up your firewall correctly.

This problem exists not only in Microsoft's firewalls, but also in other firewalls made by Symantec, Zone Alarm or other companies. Microsoft Firewall plans to replace its original ICF (Internet Connection Firewall) and starts to consider blocking all ports that are not needed by Windows services, unless you specify to open them.

When a firewall blocks a port that is in use, two problems are most likely to occur, one is that the application cannot obtain service data from the port, and the other is that the application cannot send response information to its own client program request. When there are client-side problems in FTP, streaming media, and mail applications, you should first think of these problems, as well as servers based on applications such as Web services and file services, or when you try to access a system through a terminal session or remote desktop. Keep in mind that the problem may be caused by something else, but for problems such as remote procedure calls and DCOM (distributed object component Model) settings, you should first look at the firewall settings.

When you run an application that needs to use a blocked port, a Windows Firewall security alert dialog box appears and asks if you are willing to unblock the port to allow the application to run. If you answer "Yes", the application will work properly, and the answer "No" the application will not work properly or will not run when it tries to get a service that it cannot get.

Some applications require more than one port, so problems with client programs are likely to occur because the port is blocked. On the other hand, to help you isolate these problem ports, you can use Windows's FNH (Firewall Netsh Helper) to record all dropped packets and find the ports that caused these problems with software firewall failures.

To identify these ports, you will need to view the Netstat record file, open a command line window, type "NETSTAT-ano > NETSTAT.txt", then press "Enter" and you create a NETSTAT.TXT file that records all the diary records.

Then type "TASKLIST > TASKLIST.TST" at the command prompt, click "Enter" and then type "TASKLIST > TASKLIST.TXT" to see the services loaded by each process. When you open the TASKLIST.TXT file, you should be able to use the process ID number (Process ID Number) displayed in the list to accurately locate the application you are interested in.

If you want to open another port, you need to log in to the system as a system administrator and set an exception in the firewall administrator program to unblock the port. For Windows XP's firewall, this tool is part of the Windows Security Center, which can be found in the Control Panel folder.

If you want to take advantage of the command line, open the run dialog box, type "WSCUI.CPL" and then click "OK". You should click on the "exceptions" page and add the ports you need to open, and you may also need to go through the

Use the "change scope" option to modify your open scope, which is used to set which systems can participate in this type of network communication.

Finally, you should also open the "Security Log" page so that you can see the source address of the incoming communication data, which is stored in the "% Windir%pfirewall.log" file, and the data sent will not be recorded.

After reading the above, have you mastered how to find and troubleshoot software firewalls? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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