Securing SSH server

Disable root ssh login :

edit /etc/ssh/sshd-config

locate #PermitRootLogin yes to PermitRootLogin no

save file and restart the ssh : service sshd restart

just use sudo

Trace ssh users with most Failed Login Attempts :

#cat secure* grep 'Failed password' awk '{print $9}' sort -rn uniq -c

insert this head -10 - to list top 10 failed ssh