Teach you some simple configuration to prevent the server from being attacked!

1. Add a new user and assign root privileges:
First Login with root permission
AddUser xxx (the user name you set)
passwd xxx (omit input password)
Put in the wheel group: gpasswd-a XXX Wheel
Switch to XXX User: su xxx (no permissions at this time)
With sudo in front of the command, you have the root permission operation

2. Disable the Linux root login:
sudo vim/etc/ssh/sshd_config
Permitrootlogin Yes change to Permitrootlogin no save exit
Reload Ssh:sudo Systemctl Reload sshd

3. Modify the default port of SSH link 22:
sudo vim/etc/ssh/sshd_config
Port 22 changed to Port 10000+ (random, not too big, save exit)

Reload Ssh:sudo Systemctl Reload sshd

Teach you some simple configuration to prevent the server from being attacked!