Computer "port" is the literal translation of English port, which can be regarded as the exit of computer communication with the outside world. Among them, the ports in the hardware field are also called interfaces, such as USB ports and serial ports. Ports in the software field generally refer to communication protocol ports in the network for connected services and connectionless services. They are abstract software structures, including some data structures and I/O buffers.
According to the port number can be divided into three categories:
(1) Well-known ports: from 0 to 1023, which are closely bound with some services. Usually, the communication of these ports clearly indicates the protocol of a certain service. For example, port 80 has always been HTTP communication.
(2) Registration 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.
(3) 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.