I have blocked FTP 21 port on server. NOw every connection will be via SFTP via ssh.
Initially i had
/etc/hosts.deny -- sshd:all
But i had to remove that otherwise sftp was not working.
How can i secure my shell login so that if someone login via root or userbac(root previleges)
Then i need private key but not for other users
Or any other to secure my system