What is the reason why the server cannot connect remotely?

Generally speaking, the common reasons why the server cannot connect remotely are because:
1. The bandwidth is full (not necessarily the bandwidth of the normal business, it may be abnormal packet distribution after China and Malaysia)
2. System problems: system damage caused by stuck, blue screen, loss of system files, etc.
3. After the security software is installed in the system, it is blocked without opening the corresponding protocol and port
4. The remote port number has been modified, but the system firewall rules or security software rules have not been modified
5. The remote service is not turned on
6. Being attacked by malicious DDOS and the traffic exceeds the defensive peak, the IP is blocked and has not been unblocked yet.
Troubleshooting ideas:
1. When remote connection is not possible, can the server IP be pinged (without ping prohibited)
2. When the remote connection is not possible, can the server\'s gateway IP be pinged (to judge whether it is a computer room line problem)
3. Use third-party tools to test the ping server IP and server gateway IP at the same time, you can use the multi-ping, webkaka, 17ce, etc. of the webmaster tool.
4. If the remote connection port is connected, you can use telnet+ip+port to test. For example, enter telnet 3389 under the command line