If you connect to port 3389 and enter the user name and password of the system administrator, you can operate the remote computer like this machine, so the remote server will generally modify the value of this port or close it.
If you want to continue using Remote Desktop after modifying the port number, and your computer has a firewall enabled, you must add the modified port number to the firewall exception. Otherwise, neither 3389 nor the modified port number will connect to the remote desktop.
2. Port 23 in the computer is a telnet port. Telnet protocol is a member of TCP/IP protocol family, and it is the standard protocol and main mode of Internet remote login service. It enables users to complete the remote host work on the local computer. Connect to the server using the telnet program on the end user's computer.
Using Telnet service, hackers can search for services that remotely log on to Unix and scan the type of operating system. Moreover, in Windows2000, there are many serious loopholes in the Telnet service, such as privilege elevation and denial of service, which can crash the remote server.
Extended data computer ports are divided into three categories:
I. Known ports
From 0 to 1023, it is closely bound to some services. Usually, the communication of these ports clearly shows the protocol of a service. For example, port 80 is actually always HTTP communication.
Second, register the port.
From 1024 to 49 15 1. They are loosely bound to some services. In other words, many services are bound to these ports, and these ports are also used for many other purposes. For example, many systems handle a dynamic port of about 1024.
Third, dynamic and/or dedicated ports (dynamic and/or dedicated ports)
From 49 152 to 65535. Theoretically, these ports should not be assigned to services. In fact, machines usually allocate dynamic ports from 1024. But there are exceptions: SUN's RPC port starts at 32768.
Some ports are often used by hackers and Trojan viruses to attack computer systems. The following is the introduction of computer ports and the brief methods to prevent being attacked by hackers.
Baidu encyclopedia-computer port
Baidu Encyclopedia -3389 Port
Baidu encyclopedia-port 23