I have a server where I believe I have disabled root login via ssh. I think it is done correctly, as I cannot login with root myself via ssh, but I would’ve thought that it would be reflected in /var/log/auth.log. Instead, it shows up as failed password entry. Is this intended?
What I’ve done is to uncomment the PermitRootLogin no line in /etc/ssh/sshd_config. Rest of the config file is left at default.
Bonus question: All login attempts by ssh seems to go over some random port (even my own successful logins). Why is this?
Let us see, shall we?
ssh root@cyberwolfie.com ❯ cowsay Uh-oh _______ < Uh-oh > ------- \ ^__^ \ (oo)\_______ (__)\ )\/\ ||----w | || ||;)
That all sounds correct to me. The random port you’re seeing in the logs is a high port, often referred to as an ephemeral port, and it is common for source ports. All good there.
Ok, thanks - so if I understand correctly then, it is listening on port 22 as a default, and not accepting traffic on any port.
That brings of the question: wouldn’t I be better off changing the SSH-port? And is that so easy as to uncomment the
#Port 22line in the config file and changing the port number to something random, and saving that somewhere? Would I then be able to connect by runningssh myuser@mydomain.com:, or would I need to do anything else to successfully connect?You would need to specify the new port when using ssh (using the -p$PORT option). Just keep in mind that security through obscurity is not considered secure in itself. You could instead consider a service like fail2ban that automatically blocks connections from certain sources depending on your set parameters.
Did you restart the server after you made the config change?
Yes.
