1, we often contact in the work are TCP,UDP ports are rarely used. The method for detecting whether a TCP port can be accessed outside is simple, and Telnet can test the results.
For example, Telnet www.baidu.com 80
2, like the above test Baidu Server 80 port, this can be seen is a reaction, is open to pass. If not open just like the following display.
For example, Telnet www.baidu.com 81
3, this article at the beginning of the time provided to the Psping software download, of course, you can also go to Microsoft's Web site there to download psping, this software easy to use, can test TCP or UDP are OK, very practical.
4, you can look at the use of this command method
5, use it to test the TCP port is open and communication situation
6, if the Windows system inside Telnet and psping we can open the Web page to test whether the port open communication
7. Testing UDP under Windows is really a bit of a hassle, I usually choose to test on Linux, if you want to test UDP on Windows, you can choose to install nmap for testing.