Fail2ban error

不正アクセス遮断ツールのfail2banが導入できない。

Job for fail2ban.service failed because the control process exited with error code. See "systemctl status fail2ban.service" and "journalctl -xe" for details.
#systemctl status fail2ban
● fail2ban.service - Fail2Ban Service
   Loaded: loaded (/usr/lib/systemd/system/fail2ban.service; enabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since Fri 2016-04-29 06:56:54 JST; 14s ago
     Docs: man:fail2ban(1)
  Process: 27421 ExecStart=/usr/bin/fail2ban-client -x start (code=exited, status=255)

systemd[1]: fail2ban.service: control process exited, code=exited status=255
systemd[1]: Failed to start Fail2Ban Service.
systemd[1]: Unit fail2ban.service entered failed state.
systemd[1]: fail2ban.service failed.
systemd[1]: fail2ban.service holdoff time over, scheduling restart.
systemd[1]: start request repeated too quickly for fail2ban.service
systemd[1]: Failed to start Fail2Ban Service.
systemd[1]: Unit fail2ban.service entered failed state.
systemd[1]: fail2ban.service failed.