CentOS

I've been a Linux user for many years now, initially in my teaching career at technical college, starting with early RedHat, then on to Fedora, until I discovered Centos, from version 3 onwards. I picked up a good skills set. During, and after I quit teaching, I devoted time and energy looking after...

Have you considered using VNC?

cifs-utils installed?

Do you have space in the machine to add a small 2nd drive, and put a SWAP partition on it?

You might want to use

su - "username"

not sudo,

if your intention is log use anther user's login/environment.

Simply using:

su -

with place you in root's shell.

"exit" to get out.

So you ran nmap on the server you are testing?

Because:

-A INPUT -i lo -j ACCEPT

will accept anything on localhost.

When I see users with the same name (could be me), I prefer to go about logging one off in a longwinded way.

Commands I use:

who
who am i
ps -A | grep bash

All of this should get you the users' bash PIDs.

Then kill -9 'relevant PID'.

Works for me.

Seems the problem is solved - I disabled sshd.socket.

Log files duly inspected in great detail.
All they revealed was "Deprecated option RSAAuthentication".

So I commented out the relevant entry for that in sshd_config.
I also set "UseDNS no".

So far so good.

Yesterday, after more than an hour, I still could not ssh to the server.
I have tried this with firewall on and off, no difference.