SSH as root

If you really want to ssh at root;

edit /etc/ssh/sshd_config

Find

#PermitRootLogin

[Note it may be commented out as per the example above or may have a value other than yes]

and change to

PermitRootLogin yes

Afterwards, restart ssh with

on Slackware and similar;

/etc/rc.d/rc.sshd restart [maybe stop and then restart]

or on Debian or similar;

systemctl restart ssh.service