There’s a bunch of posts about the iptables-save function of the built-in iptables module not working in many cases, so I figured it was a safer bet to suggest the playbook include an actual command invocation.

In my personal experience, the module doesnt actually save the persistent rule in about half the cases. I haven’t looked into it much, but it seems happen more on systems where systemd iptables-firewall is present. (Not trying to start a flame war)

Generally, you set up a rule + command playbook, where the command invokes the iptables-save command.

I read the old thread and now this one.

As I understand it, you want to create connection between clients on your lan, but you don’t trust your lan, so it’s like having a raspberry pi server and some client both on the coffee shop network and you want them to communicate securely?

Tailscale is what you want. Easy setup, free, and allows exactly this to happen.

Do you have port 80 to nginx open? Certbot dry run will give you some diagnostics, but that is the most common issue (port 80 being closed).

I also run LE on nginx and afraid DNS.