[27759]: ОШИБКА Не удалось выполнить действие запрета jail 'sshd' в журнале fail2ban

На моем сервере Debian 8 я часто вижу эту ошибку в журнале fail2ban .

 [27759]: ERROR   Failed to execute ban jail 'sshd' action 'iptables-multiport' info 'ActionInfo({'ip': '1.1.2.2', 'fam
ily': 'inet4', 'ip-rev': '2.2.1.1.', 'ip-host': '210994.cloudwaysapps.com', 'fid': '1.1.2.2', 'failures': 3, 'time': 1547974803.0, 'matches': 'Jan 20 04:00:01
 chat sshd[1326]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=1.1.2.2 \nJan 20 04:00:03 chat sshd[1326]: Failed password f
or invalid user guest from 1.1.2.2 port 40633 ssh2', 'restored': 0, 'F-*': {'matches': ['Jan 20 04:00:01 chat sshd[1326]: pam_unix(sshd:auth): authentication failure;
 logname= uid=0 euid=0 tty=ssh ruser= rhost=1.1.2.2 ', 'Jan 20 04:00:03 chat sshd[1326]: Failed password for invalid user guest from 1.1.2.2 port 40633 ssh2']
, 'failures': 3, 'mlfid': ' chat sshd[1326]: ', 'user': 'guest', 'ip4': '1.1.2.2'}, 'ipmatches': 'Jan 20 04:00:01 chat sshd[1326]: pam_unix(sshd:auth): authentication
 failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=1.1.2.2 \nJan 20 04:00:03 chat sshd[1326]: Failed password for invalid user guest from 1.1.2.2 port 40633
 ssh2', 'ipjailmatches': 'Jan 20 04:00:01 chat sshd[1326]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=1.1.2.2 \nJan 20 04
:00:03 chat sshd[1326]: Failed password for invalid user guest from 1.1.2.2 port 40633 ssh2', 'ipfailures': 3, 'ipjailfailures': 3})': Error banning 1.1.2.2
2019-01-20 04:01:24,018 fail2ban.actions  

Мне интересно, что означает эта ошибка и как ее исправить?