I'm new to Docker and Portainer and am running several containers, including Jellyfin, on a Synology NAS. The containers work correctly on my local network, but I can't reach Jellyfin remotely. I'm using DuckDNS, have configured the containers, and forwarded the necessary ports. Online port-checking tools show the ports as open, but external access still fails. I also created a Windows script that works when a terminal stays open, although I'd prefer a persistent solution.
I'm also running Nginx Proxy Manager and have been trying to obtain Let's Encrypt certificates. Certificate requests fail with an internal error most of the time, and even when one succeeds, the proxy setup still doesn't provide remote access. I've since removed the containers and pruned the Docker setup, so I'm looking for a clear way to rebuild and troubleshoot this from the basics.
2 Answers
A custom domain can be easier than DuckDNS, especially if you use a DNS provider that Nginx Proxy Manager supports. Point the domain to your home connection, configure the proxy host for Jellyfin, and make sure ports 80 and 443 reach the proxy container. For certificates, the domain must resolve correctly and port 80 must be reachable during HTTP validation; otherwise Let’s Encrypt will fail. A local DNS service can also provide split DNS, letting the same hostname resolve to the internal address while you’re at home, but get basic external access working first. Traefik is another option, though switching proxy software won’t fix an underlying port-forwarding or DNS issue.
This is probably best troubleshot as a network-connectivity problem before changing more Docker settings. First verify that the service is reachable from outside your home network, such as from a computer connected through a phone hotspot. Test the NAS’s forwarded port directly, then test Jellyfin locally, and only afterward add Nginx Proxy Manager and certificates. Breaking it into those layers should show whether the problem is the router, firewall, Docker networking, or the reverse proxy.
I’m still learning the networking side, so I’ll need to start with a very basic test and add the containers back one piece at a time.
I’ve used a purchased domain before but still couldn’t get it working, and DNS tools have been confusing. I’ll avoid adding Pi-hole or another DNS service until the basic proxy and external connection are working.