我对 iptables 和 fail2ban 都只有一点点了解，但我的邮件服务器有很多我想摆脱的传入连接。
我在 /etc/fail2ban/jail.conf 中有这个配置块
[postfix-sasl]
enabled = true
port = smtp,465,submission,imap3,imaps,pop3,pop3s
logpath = %(postfix_log)s
backend = %(postfix_backend)s
但我认为，虽然正确检测到了禁令，但根本没有效果，因为我看到 fail2ban 日志报告了 iptables 错误，这里是 fail2ban 启动后并尝试恢复先前发现的禁令的一段日志：
2018-01-22 14:53:23,365 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- stdout: b''
2018-01-22 14:53:23,365 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- stderr: b"iptables v1.6.0: invalid port/service `smtp,465,submission,imap3,imaps,pop3,pop3s' specified\nTry `iptables -h' or 'iptables --help' for more information.\n"
2018-01-22 14:53:23,366 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- returned 2
2018-01-22 14:53:23,366 fail2ban.actions [26127]: ERROR Failed to start jail 'postfix-sasl' action 'iptables': Error starting action
2018-01-22 14:53:23,366 fail2ban.actions [26127]: NOTICE [postfix-sasl] Ban 80.82.70.210
2018-01-22 14:53:23,470 fail2ban.action [26127]: ERROR iptables -w -n -L INPUT | grep -q 'f2b-postfix-sasl[ \t]' -- stdout: b''
2018-01-22 14:53:23,470 fail2ban.action [26127]: ERROR iptables -w -n -L INPUT | grep -q 'f2b-postfix-sasl[ \t]' -- stderr: b''
2018-01-22 14:53:23,471 fail2ban.action [26127]: ERROR iptables -w -n -L INPUT | grep -q 'f2b-postfix-sasl[ \t]' -- returned 1
2018-01-22 14:53:23,471 fail2ban.CommandAction [26127]: ERROR Invariant check failed. Trying to restore a sane environment
2018-01-22 14:53:23,679 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- stdout: b''
2018-01-22 14:53:23,680 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- stderr: b"iptables v1.6.0: invalid port/service `smtp,465,submission,imap3,imaps,pop3,pop3s' specified\nTry `iptables -h' or 'iptables --help' for more information.\n"
2018-01-22 14:53:23,680 fail2ban.action [26127]: ERROR iptables -w -N f2b-postfix-sasl
iptables -w -A f2b-postfix-sasl -j RETURN
iptables -w -I INPUT -p tcp --dport smtp,465,submission,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl -- returned 2
2018-01-22 14:53:23,680 fail2ban.actions [26127]: ERROR Failed to execute ban jail 'postfix-sasl' action 'iptables' info 'CallingMap({'failures': 2, 'time': 1516629203.366475, 'matches': 'Jan 22 14:05:12 ysengr postfix/smtpd[25386]: warning: unknown[80.82.70.210]: SASL LOGIN authentication failed: UGFzc3dvcmQ6\nJan 22 14:05:59 ysengr postfix/smtpd[25386]: warning: unknown[80.82.70.210]: SASL LOGIN authentication failed: UGFzc3dvcmQ6', 'ip': '80.82.70.210', 'ipmatches': <function Actions.__checkBan.<locals>.<lambda> at 0xb6a5c344>, 'ipjailmatches': <function Actions.__checkBan.<locals>.<lambda> at 0xb6a5c38c>, 'ipjailfailures': <function Actions.__checkBan.<locals>.<lambda> at 0xb6a5c41c>, 'ipfailures': <function Actions.__checkBan.<locals>.<lambda> at 0xb6a5c3d4>})': Error starting action
我尝试阅读了这篇文章，但无法从中获得任何有价值的信息。有人能帮我正确设置吗？非常感谢
编辑：这是两个软件的版本
root@ysengr:/etc/fail2ban# fail2ban-server -V
Fail2Ban v0.9.6
Copyright (c) 2004-2008 Cyril Jaquier, 2008- Fail2Ban Contributors
Copyright of modifications held by their respective authors.
Licensed under the GNU General Public License v2 (GPL).
Written by Cyril Jaquier <[email protected]>.
Many contributions by Yaroslav O. Halchenko <[email protected]>.
root@ysengr:/etc/fail2ban# iptables -V
iptables v1.6.0
按照指示，我重置了banactioniptables 多端口，但日志显示相同的错误。这次在单独的终端中运行日志中报告的 iptables 命令行，它给了我以下内容：
root@ysengr:/etc/fail2ban# iptables -w -I INPUT -p tcp -m multiport --dports 25,465,587,imap3,imaps,pop3,pop3s -j f2b-postfix-sasl
iptables v1.6.0: invalid port/service `imap3' specified
确实，imap3 不存在，/etc/services所以我像这样添加了它
root@ysengr:/etc/fail2ban# grep imap3 /etc/services
imap2 143/tcp imap imap3 # Interim Mail Access P 2 and 4
答案1
为了禁止多个端口，您banaction需要将其设置为iptables-multiport。这是默认值，但根据您显示的日志输出，您显然将其设置为其他值。
尝试重置banaction = iptables-multiport。