The TCP-IP has reached the security limit for the number of concurrent TCP connection attempts

To prevent the spread and attack of the worm, Windows XP SP2 limits the number of concurrent threads to a maximum of 10. SP2 uses the messages dynamic link library to monitor the number of concurrent threads of each process in real time. Once it finds that the number of threads of a process exceeds 10, some threads are blocked. In this way, SP2 can prevent the shock wave type worms and enhance system security, but it also has some negative effects, such as when you download the BT, P2P, or flashget software, some threads will be blocked, so the download speed will become very slow, and some will also disconnect the network. To this end, you can take the following measures to break through the number of concurrent TCP connections, thus improving the multi-thread access speed of SP2.

1. Registry Modification Method (this method is invalid after testing and cannot increase the maximum number of concurrent TCP connections)

To break through the limits of SP2 on the number of concurrent TCP connections, a method to modify the Registry has been circulated on the Internet. The procedure is as follows:

Click Start/run, enter Regedit to open the registry, and locate the modified tcpnumconnections key value under HKEY_LOCAL_MACHINE/system/CurrentControlSet/services/TCPIP/parameters, change it from 10 to 150, that is, set the maximum number of concurrent TCP connections to 150.

After actual tests, we found that this method looks effective, but in essence it cannot break through the limit on concurrent connections, improving the multi-thread access speed of SP2. Because SP2 controls the number of threads through "tcpip. sys "is implemented by the system file instead of the Registry. Therefore, this method cannot increase the number of TCP concurrent connections of SP2.

2. Use a tool to replace tcpip. sys (I think it is the best)

To break through the TCP concurrent connections limit of SP2, the correct method is to modify the system file tcpip. sys of Windows XP SP2. Tcpip. sys is an important system file of Windows XP SP2, which is located in the "C:/Windows/system32/DRIVERS directory. Because the file is usually protected by the system, you cannot replace it normally. It must be replaced in safe or pure DOS mode, we recommend that you use the following special tools to replace "tcpip. the operation steps are as follows:

Http://www.lvllord.de/download.php from the web? Url = EN/EvID4226Patch223d-en.zip download replacement tool (only 30 kb), use it to modify the system file tcpip. sys maximum secure concurrent connection limit; then back up C:/Windows/system32/

Drivers/tcpip. SYS file.

Next, double-click the downloaded zip package and run the replacement tool evid4226patch.exe. a command line Prompt window is displayed, showing the current TCPIP of windows. the sys file version and the maximum number of concurrent connections (10 by default). Then, ask if you want to limit the number of connections to 50. You can select "yes/no/Change ", if you enter "Y", the number of concurrent connections is changed to "50". If you want to change it to another number (such as 150), you can enter "C" at the prompt ", enter the maximum number of concurrent connections (for example, 150) and press Enter. Then, enter "Y" at the prompt and press enter to replace tcpip. sys File; tcpip. after the Sys File is replaced, the System File Protection dialog box will pop up. You can click "cancel" and then click "yes". After the system file is restarted, tcpip. replace the Sys File!

Now your maximum number of concurrent connections has exceeded 10 to 150, so the multi-thread access speed of Windows XP SP2 has been improved. When you use multiple threads such as flashget and Bt for download, you will not feel the limit on network bandwidth.

3. Modify the tcpip. SYS file under DOS (this method works well, but dos operation is required)

The replacement program evid4226patch.exe can also be used in DOS by copying evid4226patch.exe to the c root directory first, and then entering the DOS mode to enter the C root directory, enter the command evid4226patch/L =n N $/W = C:/Windows/system32/Drivers/L = tcpip. sys to modify the tcpip. sys File.

Note: The above $ N $ is the maximum number of secure connections you want to set. If you want to set the maximum number of concurrent connections to 150 threads, enter the command evid4226patch/L = 150/W = C: /Windows/system32/Drivers/L = tcpip. SYS.

4. Use the tool provided by the IOT platform (for operating systems that do not update the system)

Tcpip. sys can be replaced by the tool "TCP/IP connection cracking patch" provided by Iot platform, which breaks through the TCP concurrent connection limit of SP2.

Http://download.pchome.net/php/dl.php from the web? SID = 15504 download bitspirit v2.7.2.225 Simplified Chinese official version, and then double-click the download file to install it. You can choose which components to install and install the "patch for cracking TCP/IP connections for Windows XP SP2". After the installation is complete, the bitspirit Program Group will appear in the XP Start Menu, click the "XP SP2 connection cracking patch" to modify the tcpip. sys File.

Click the "XP SP2 connection cracking patch" to bring up the software interface, which lists the current tcpip. you can enter a number in "TCP/IP linitation" to set the maximum number of concurrent connections. For example, enter 150, and then press "Apply, after the system is restarted, the maximum number of concurrent connections of your sp2 server is changed to 150.

The preceding Methods increase the multi-thread access speed of Windows XP SP2, but reduce the security performance of SP2. If your computer is infected with viruses and Trojans, too many new threads are enabled, it will accelerate the spread of viruses and Trojans. Therefore, you must pay attention to network security while pursuing the speed of network download. We recommend that you install and Upgrade anti-virus software and firewall in a timely manner. If you are a common user, you can use the above method to set the maximum number of concurrent TCP connections to 10 ~ 30, BT users can be set to 100 ~ 150.