Getting Error when trying to generate ACME certificates

I'm getting an error claiming there is a timeout during connect (likely firewall problem) when trying to generate ACME certificates with let's encrypt. I do have a firewall between traefik and the world, however I do have ports 80 and 443 forwarded to the machines running traefik, and when I set up a different container using those ports it still works. I've tried moving traefik to a different machine with no luck. And reverse-proxy doesn't work from outside in. Internally it works.

Need some configuration files and some logs. Just as a note: I get an error 400 when my acme.json is completely empty in first run. Logs show error 400 and acme.json only has a snippet of info about my cloudflare email but nothing about my domain but after I up/down Traefik it pulls everything else. I'm not suggesting you have the same problem but there is definitely some trickery at work with cert pulling.

Hello, it's possible that the environment within the Traefik container is unable to make contact with the outside world, this is required to initiate a handshake with LE.

Please post your logs and configuration which we could possibly use to reproduce the problem.