When I type in service sshd restart I get a sshd: unrecognized service error. I do have, in /etc/ssh/ a file sshd_config that I use to set config. I can also putty into the Ubuntu box (it is remote). ...
I need to forbid ssh access (except localhost) for specified user. So. ssh localhost should work. ssh hostname from outside should not work for that user. All other users should work as usual.