Permit Root Login Via SSH
1.Edit /etc/ssh/sshd_config with sudo or root privilege
$ sudo vim /etc/ssh/sshd_config
2.Uncomment “#PermitRootLogin without-password”, Add “PermitRootLogin yes”
# Authentication:
LoginGraceTime 120
#PermitRootLogin without-password
PermitRootLogin yes
StrictModes yes
3.Restart SSH Service
# service ssh restart
Or
# systemctl restart ssh