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?
Not sure what you meant about the ‘match’ config expressions here. Could you elaborate a bit further?
Hehe, yeah, I’ve noticed… The reason I get a little anxious whether I did this correctly, is that 95% of the login attempts are to root, so I want to make sure it is disabled. I have set up Fail2Ban, but I am using default settings, which may be a bit laxer than they need?
I’ve also been advised and considered moving to ssh keys, but I have not gotten to that yet.
Makes sense. One question that comes from this is: is it possible to disable that? I would never need two ssh-logins at the same time on my server. And the second question is what I asked above regarding whether I should change the port ssh listens to in order to reduce unwanted malicious login attempts?
No, it’s nonsense. Nothing like that happens.
Match blocks allow you to restrict who/what is allowed or not allowed to connect to the server. There is a large number of options to utilize. Put this near the bottom of sshd_config. There should be an example there.
Here are some more examples: https://stackoverflow.com/questions/10829712/sshd-with-multiple-match-sections-override-settings
Thanks - I’ll look more into that to see if I can make any rules that would make sense for my use case.