A very insistent individual is trying continuously to gain (unauthorized) access to my system for the last few days... There are a gazillion of entries, like in /var/log/auth.log
:
Jun 21 03:55:15 cloudy sshd[32487]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=116.31.116.20 user=root
Jun 21 03:55:16 cloudy sshd[32487]: Failed password for root from 116.31.116.20 port 30629 ssh2
Jun 21 03:55:19 cloudy sshd[32487]: Failed password for root from 116.31.116.20 port 30629 ssh2
Jun 21 03:55:21 cloudy sshd[32487]: Failed password for root from 116.31.116.20 port 30629 ssh2
Jun 21 03:55:21 cloudy sshd[32487]: Received disconnect from 116.31.116.20: 11: [preauth]
Jun 21 03:55:21 cloudy sshd[32487]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=116.31.116.20 user=root
I would like to ask for some advice on how to block this individual from consuming resources from the computer, is there a possibility to "hard block" the IP from even opening an ssh connection? Please note, I use Debian 8 as OS.