Background: I'm trying to configure an ubuntu server to run a node.js application with https. I previously had everything working fine with http (configured a year ago), and I wanted to open the firewall for :443 and redirect it to :8443:
sudo ufw allow 443/tcp
sudo iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8443
When trying out my app, it turned out the https request didn't register with the app (nothing in the app-logs, and browser never gets a response to the request). When I ping the server, I also don't get a response (it doesn't even time out). My cloud provider dashboard also states that it can't ping the server, and the cloud provider firewall config also says 443 is allowed for all tcp. ... But, I can still ssh onto the server without an issue.
Question How can I troubleshoot this? As far as I can tell
- :443 is allowed on the firewall
- :443 redirects to :8443
- node is listening to :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