Start-Run-Enter command. After entering DOS, enter netstat -an to display port usage, TCP for connection-oriented service, UDP for connectionless service, service content, port number and port status corresponding to each service, LISTENNING for monitoring, ESTABLISHED for connection established, and TIME WAIT for timeout. IE browser generally uses port 80, but as a general network name, it is difficult to see the network usage from the port usage, because the description of the service is not very detailed, and general firewall, antivirus software and other software connecting to the network use a large number of discontinuous ports. Looking at the port can also identify some Trojans, because ordinary Trojans will use some unusual ports. Most similar Trojans often use the same port to provide services. So even if you can check the port, you will still be confused after reading it. The safest way is to call the network operator, and they will send network installers to solve your problem. Time depends on the service quality and efficiency of local network operators. The following are some common reasons for network disconnection.

1. There are problems with the network server, including the operator server (rarely, but occasionally) and the community server. Generally, if you don't call the network operator in advance, it will be very disadvantageous. You spent a lot of time looking for your own computer and found that they had problems. Are you angry? It may not be possible, but it's not good for you to break the computer yourself.

2. There is something wrong with the wiring. General home broadband access is connected to the separator through telephone lines, and the separator is divided into two lines, one for answering the phone and the other for answering the cat. However, if another phone is connected to the front of the separator, the phone will be disconnected when answering and dialing. The solution is to connect the mobile phone to the line behind the separator.

There is something wrong with cats, including cats themselves. Just change a cat. Another reason for the disconnection is that the cat's driver is not installed correctly. The driven cat has many agreements. If used improperly, it will be disconnected. Of course, he can surf the Internet, but it is unstable.

If you are infected with virus, some viruses will cause you to disconnect from the Internet.

There are various situations of disconnection, so it is best to find the network operator first.