背景： 我正在尝试配置一个 ubuntu 服务器以使用 https 运行 node.js 应用程序。我以前使用 http 一切正常（一年前配置的），我想打开 :443 的防火墙并将其重定向到 :8443：
sudo ufw allow 443/tcp
sudo iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8443
试用我的应用程序时，结果发现 https 请求未在应用程序中注册（应用程序日志中没有任何内容，浏览器从未收到对请求的响应）。当我 ping 服务器时，我也没有收到响应（它甚至没有超时）。我的云提供商仪表板也显示无法 ping 服务器，云提供商防火墙配置也显示 443 允许所有 tcp。...但是，我仍然可以毫无问题地 ssh 到服务器上。
问题 我该如何解决这个问题？据我所知
- :443 在防火墙上被允许
- :443 重定向至 :8443
- 节点正在监听：8443
sudo ufw status
To Action From
-- ------ ----
80/tcp ALLOW Anywhere
443/tcp ALLOW Anywhere
80/tcp (v6) ALLOW Anywhere (v6)
443/tcp (v6) ALLOW Anywhere (v6)
sudo iptables -t nat -L -n -v
Chain PREROUTING (policy ACCEPT 9477 packets, 1121K bytes)
pkts bytes target prot opt in out source destination
1413K 59M REDIRECT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
0 0 REDIRECT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
0 0 REDIRECT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
0 0 REDIRECT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
0 0 REDIRECT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
0 0 REDIRECT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443 redir ports 8443
Chain INPUT (policy ACCEPT 6826 packets, 410K bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 74 packets, 6925 bytes)
pkts bytes target prot opt in out source destination
Chain POSTROUTING (policy ACCEPT 74 packets, 6925 bytes)
pkts bytes target prot opt in out source destination
sudo netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN 108911/systemd-reso
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 112287/sshd
tcp 0 0 0.0.0.0:1022 0.0.0.0:* LISTEN 125785/sshd
tcp6 0 0 :::22 :::* LISTEN 112287/sshd
tcp6 0 0 :::8443 :::* LISTEN 125414/node
tcp6 0 0 :::1022 :::* LISTEN 125785/sshd
sudo iptables -L -nv
Chain INPUT (policy DROP 120 packets, 30108 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:8443
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:8443
381K 34M ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:8443
998 94467 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080
8163 1107K ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
54M 15G ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2892K 172M ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22
Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 5873 packets, 874K bytes)
pkts bytes target prot opt in out source destination
Chain ufw-after-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-logging-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-logging-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-logging-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-logging-allow (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-logging-deny (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-not-local (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-input (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443
Chain ufw-user-limit (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-limit-accept (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-output (0 references)
pkts bytes target prot opt in out source destination
答案1
重新启动 ufw。
sudo systemctl restart ufw
您的 iptables 输出显示，ufw 添加的大多数规则都丢失了。这是由于sudo iptables -F在 ufw 仍在运行时手动刷新表（例如）造成的，这当然也会刷新 ufw 的规则并导致大量破坏，但随机的互联网教程会告诉您这样做。