The IP 123.30.242.51 has just been banned by Fail2Ban after 19 attempts against SSH. Latest lines containing IP:123.30.242.51 in /var/log/syslog/sshd.log Aug 13 21:48:10 ftlogin2 sshd[22743]: Failed keyboard-interactive/pam for invalid user admin from 123.30.242.51 port 56901 ssh2 Aug 13 21:48:21 ftlogin2 sshd[22751]: Address 123.30.242.51 maps to static.vdc.vn, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT! Aug 13 21:48:21 ftlogin2 sshd[22751]: Invalid user admin from 123.30.242.51 Aug 13 21:48:21 ftlogin2 sshd[22754]: Postponed keyboard-interactive for invalid user admin from 123.30.242.51 port 57183 ssh2 Aug 13 21:48:23 ftlogin2 sshd[22751]: error: PAM: User not known to the underlying authentication module for illegal user admin from 123.30.242.51 Aug 13 21:48:23 ftlogin2 sshd[22751]: Failed keyboard-interactive/pam for invalid user admin from 123.30.242.51 port 57183 ssh2 Aug 13 21:48:23 ftlogin2 sshd[22754]: Postponed keyboard-interactive for invalid user admin from 123.30.242.51 port 57183 ssh2 Aug 13 21:48:24 ftlogin2 sshd[22751]: error: PAM: User not known to the underlying authentication module for illegal user admin from 123.30.242.51 Aug 13 21:48:24 ftlogin2 sshd[22751]: Failed keyboard-interactive/pam for invalid user admin from 123.30.242.51 port 57183 ssh2 Aug 13 21:48:24 ftlogin2 sshd[22754]: Postponed keyboard-interactive for invalid user admin from 123.30.242.51 port 57183 ssh2 - Fail2ban on