Again, the target for logging in with ssh is Ubuntu 18.04. What I did to increase security
# vim /etc/ssh/sshd_config
Open the config file with, look for
Port 22 and enter any port
There are well-known ports, so let's think about it.
By the way, if you do not remove #, it will be commented out, so don't forget to remove it.
However, this alone cannot be changed, so
Let's add a new port number to SELinux policy and change the firewalld settings as well.
This area will come out as soon as you check it.
PermitRootLogin in the same way and set it to
I will write here later