我有两台 Ubuntu 服务器，它们具有相同的 Samba 配置和相同的 Samba 端口 UFW 规则，但区别在于，一台使用 14.04 版本运行正常，而另一台使用 12.04 版本则拒绝从任何地方访问。
在 12.04 服务器上禁用 UFW 后，Samba 连接再次被允许。但是，在启用 UFW 后，UFW 日志中没有来自块的日志条目。
我该如何调试这个问题？
编辑：我发现了这些iptables用于smb和dhcp端口的规则：
:ufw-skip-to-policy-input - [0:0]
-A ufw-after-input -p udp -m udp --dport 137 -j ufw-skip-to-policy-input
-A ufw-after-input -p udp -m udp --dport 138 -j ufw-skip-to-policy-input
-A ufw-after-input -p tcp -m tcp --dport 139 -j ufw-skip-to-policy-input
-A ufw-after-input -p tcp -m tcp --dport 445 -j ufw-skip-to-policy-input
-A ufw-after-input -p udp -m udp --dport 67 -j ufw-skip-to-policy-input
-A ufw-after-input -p udp -m udp --dport 68 -j ufw-skip-to-policy-input
-A ufw-after-input -m addrtype --dst-type BROADCAST -j ufw-skip-to-policy-input
-A ufw-skip-to-policy-input -j DROP
然而，将它们移除并/etc/ufw/after.rules没有什么作用。
这是当前iptables-save输出：
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
:fail2ban-apache - [0:0]
:fail2ban-apache-noscript - [0:0]
:fail2ban-apache-overflows - [0:0]
:fail2ban-dovecot - [0:0]
:fail2ban-postfix - [0:0]
:fail2ban-ssh - [0:0]
:fail2ban-ssh-ddos - [0:0]
:fail2ban-wuftpd - [0:0]
:ufw-after-forward - [0:0]
:ufw-after-input - [0:0]
:ufw-after-logging-forward - [0:0]
:ufw-after-logging-input - [0:0]
:ufw-after-logging-output - [0:0]
:ufw-after-output - [0:0]
:ufw-before-forward - [0:0]
:ufw-before-input - [0:0]
:ufw-before-logging-forward - [0:0]
:ufw-before-logging-input - [0:0]
:ufw-before-logging-output - [0:0]
:ufw-before-output - [0:0]
:ufw-logging-allow - [0:0]
:ufw-logging-deny - [0:0]
:ufw-not-local - [0:0]
:ufw-reject-forward - [0:0]
:ufw-reject-input - [0:0]
:ufw-reject-output - [0:0]
:ufw-skip-to-policy-forward - [0:0]
:ufw-skip-to-policy-input - [0:0]
:ufw-skip-to-policy-output - [0:0]
:ufw-track-input - [0:0]
:ufw-track-output - [0:0]
:ufw-user-forward - [0:0]
:ufw-user-input - [0:0]
:ufw-user-limit - [0:0]
:ufw-user-limit-accept - [0:0]
:ufw-user-logging-forward - [0:0]
:ufw-user-logging-input - [0:0]
:ufw-user-logging-output - [0:0]
:ufw-user-output - [0:0]
-A INPUT -p tcp -m multiport --dports 25,465,143,220,993,110,995 -j fail2ban-dovecot
-A INPUT -p tcp -m multiport --dports 25,465 -j fail2ban-postfix
-A INPUT -p tcp -m multiport --dports 21,20,990,989 -j fail2ban-wuftpd
-A INPUT -p tcp -m multiport --dports 80,443 -j fail2ban-apache-overflows
-A INPUT -p tcp -m multiport --dports 80,443 -j fail2ban-apache-noscript
-A INPUT -p tcp -m multiport --dports 80,443 -j fail2ban-apache
-A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh-ddos
-A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh
-A INPUT -j ufw-before-logging-input
-A INPUT -j ufw-before-input
-A INPUT -j ufw-after-input
-A INPUT -j ufw-after-logging-input
-A INPUT -j ufw-reject-input
-A INPUT -j ufw-track-input
-A FORWARD -j ufw-before-logging-forward
-A FORWARD -j ufw-before-forward
-A FORWARD -j ufw-after-forward
-A FORWARD -j ufw-after-logging-forward
-A FORWARD -j ufw-reject-forward
-A OUTPUT -j ufw-before-logging-output
-A OUTPUT -j ufw-before-output
-A OUTPUT -j ufw-after-output
-A OUTPUT -j ufw-after-logging-output
-A OUTPUT -j ufw-reject-output
-A OUTPUT -j ufw-track-output
-A fail2ban-apache -j RETURN
-A fail2ban-apache-noscript -j RETURN
-A fail2ban-apache-overflows -j RETURN
-A fail2ban-dovecot -j RETURN
-A fail2ban-postfix -j RETURN
-A fail2ban-ssh -j RETURN
-A fail2ban-ssh-ddos -j RETURN
-A fail2ban-wuftpd -j RETURN
-A ufw-after-input -m addrtype --dst-type BROADCAST -j ufw-skip-to-policy-input
-A ufw-after-logging-forward -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[UFW BLOCK] "
-A ufw-after-logging-input -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[UFW BLOCK] "
-A ufw-before-forward -j ufw-user-forward
-A ufw-before-input -i lo -j ACCEPT
-A ufw-before-input -m state --state RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-input -m state --state INVALID -j ufw-logging-deny
-A ufw-before-input -m state --state INVALID -j DROP
-A ufw-before-input -p icmp -m icmp --icmp-type 3 -j ACCEPT
-A ufw-before-input -p icmp -m icmp --icmp-type 4 -j ACCEPT
-A ufw-before-input -p icmp -m icmp --icmp-type 11 -j ACCEPT
-A ufw-before-input -p icmp -m icmp --icmp-type 12 -j ACCEPT
-A ufw-before-input -p icmp -m icmp --icmp-type 8 -j ACCEPT
-A ufw-before-input -p udp -m udp --sport 67 --dport 68 -j ACCEPT
-A ufw-before-input -j ufw-not-local
-A ufw-before-input -d 224.0.0.251/32 -p udp -m udp --dport 5353 -j ACCEPT
-A ufw-before-input -d 239.255.255.250/32 -p udp -m udp --dport 1900 -j ACCEPT
-A ufw-before-input -j ufw-user-input
-A ufw-before-output -o lo -j ACCEPT
-A ufw-before-output -m state --state RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-output -j ufw-user-output
-A ufw-logging-allow -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[UFW ALLOW] "
-A ufw-logging-deny -m state --state INVALID -m limit --limit 3/min --limit-burst 10 -j RETURN
-A ufw-logging-deny -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[UFW BLOCK] "
-A ufw-not-local -m addrtype --dst-type LOCAL -j RETURN
-A ufw-not-local -m addrtype --dst-type MULTICAST -j RETURN
-A ufw-not-local -m addrtype --dst-type BROADCAST -j RETURN
-A ufw-not-local -m limit --limit 3/min --limit-burst 10 -j ufw-logging-deny
-A ufw-not-local -j DROP
-A ufw-skip-to-policy-forward -j DROP
-A ufw-skip-to-policy-input -j DROP
-A ufw-skip-to-policy-output -j ACCEPT
-A ufw-track-output -p tcp -m state --state NEW -j ACCEPT
-A ufw-track-output -p udp -m state --state NEW -j ACCEPT
-A ufw-user-input -p tcp -m multiport --dports 80,443 -m comment --comment "\'dapp_Apache%20Full\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 53 -m comment --comment "\'dapp_Bind9\'" -j ACCEPT
-A ufw-user-input -p udp -m udp --dport 53 -m comment --comment "\'dapp_Bind9\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 143 -m comment --comment "\'dapp_Dovecot%20IMAP\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 110 -m comment --comment "\'dapp_Dovecot%20POP3\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 22 -m comment --comment "\'dapp_OpenSSH\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 25 -m comment --comment "\'dapp_Postfix\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 465 -m comment --comment "\'dapp_Postfix%20SMTPS\'" -j ACCEPT
-A ufw-user-input -p tcp -m tcp --dport 587 -m comment --comment "\'dapp_Postfix%20Submission\'" -j ACCEPT
-A ufw-user-input -p udp -m multiport --dports 137,138 -m comment --comment "\'dapp_Samba\'" -j ACCEPT
-A ufw-user-input -p tcp -m multiport --dports 139,445 -m comment --comment "\'dapp_Samba\'" -j ACCEPT
-A ufw-user-limit -m limit --limit 3/min -j LOG --log-prefix "[UFW LIMIT BLOCK] "
-A ufw-user-limit -j REJECT --reject-with icmp-port-unreachable
-A ufw-user-limit-accept -j ACCEPT
COMMIT
答案1
在底层，UFW 仅指导 iptables/netfilter，因此适用通常的规则。
第一条规则数据包匹配反对胜利。
和 Samba 端口相同的 UFW 规则
您的 SMB 相关数据包可能与阻止访问的早期规则匹配。
我该如何调试这个问题？
您必须审核您的防火墙规则，了解它们，然后做出适当的更改。