我已经使用本教程为我的Ubuntu 16.04服务器安装了fail2ban。
经历了这个后，我试着开始：/etc/init.d/fail2ban start
以下是回复：
[....] Starting fail2ban (via systemctl): fail2ban.serviceJob for fail2ban.service failed because the control process exited with error code. See "systemctl status fail2ban.service" and "journalctl -xe" for details.
失败！
然后我运行：systemctl status fail2ban.service
我明白了：
> fail2ban.service - Fail2Ban Service
Loaded: loaded (/lib/systemd/system/fail2ban.service; enabled; vendor preset: enabled)
Active: inactive (dead) (Result: exit-code) since Tue 2018-05-15 14:01:38 UTC; 1min 40s ago
Docs: man:fail2ban(1)
Process: 4468 ExecStart=/usr/bin/fail2ban-client -x start (code=exited, status=255)
May 15 14:01:38 tastycoders-prod1 systemd[1]: fail2ban.service: Control process exited, code=exited status=255
May 15 14:01:38 tastycoders-prod1 systemd[1]: Failed to start Fail2Ban Service.
May 15 14:01:38 tastycoders-prod1 systemd[1]: fail2ban.service: Unit entered failed state.
May 15 14:01:38 tastycoders-prod1 systemd[1]: fail2ban.service: Failed with result 'exit-code'.
May 15 14:01:38 tastycoders-prod1 systemd[1]: fail2ban.service: Service hold-off time over, scheduling restart.
May 15 14:01:38 tastycoders-prod1 systemd[1]: Stopped Fail2Ban Service.
May 15 14:01:38 tastycoders-prod1 systemd[1]: fail2ban.service: Start request repeated too quickly.
May 15 14:01:38 tastycoders-prod1 systemd[1]: Failed to start Fail2Ban Service.
答案 0 :(得分：0)
DigitalOcean的一些教程包含错误。检查您的/etc/fail2ban/jail.local。尽量保持简单，即只保留那些你想要改变的选项。
否则，如果您已将jail.conf复制到jail.local（根据DO的指南），则在jail.local中删除或注释掉pam部分（如果您不使用它）文件。
转到/etc/fail2ban/jail.local
的第146行# [pam-generic]
# enabled = false
# pam-generic filter can be customized to monitor specific subset of 'tty's
# filter = pam-generic
# port actually must be irrelevant but lets leave it all for some possible uses
# port = all
# banaction = iptables-allports
# port = anyport
# logpath = /var/log/auth.log
# maxretry = 6