SSH is a secure Shell.

Developed by IETF's network working group;

SSH is a security protocol based on application layer and transport layer.

The data transmitted by SSH is encrypted, which can effectively prevent the transmission process from being intercepted and ensure the security of data.

SSH data is compressed, so it can speed up the transmission.

1

First, check whether the SSH package has been installed in linux, and use rpm-QA | grepsash.

2. Confirm that the ssh service has been started.

3. Find the SShD _ config file in the /etc/ssh directory.

Edit and modify SSH port numbers

1. Using the VI \vim editor, open the file sshd_config and search to find the port field.

2 Set the cursor to yy in port 22, then copy a line on keyboard P, and insert Edit 22, with port 2222.

After setting 3, wq saves and exits, indicating that port number 2222 has been added.

4. Of course, after the setup is completed, you need to restart the SSH service.

5. If you have set a firewall, please modify the rules for adding a firewall, or turn it off directly.

Matters needing attention

By default, SSH port is 22. If you want to modify, edit port 22 directly. Note that the front "#" should be removed, then saved and restarted.