So, I've been having issues with port forwarding from external addresses on my Plex Server with UNRAID.

 

The ports for the docker are:

 

I want it to run externally on port 54321, so the route should look like this:

Internet -> 54321 -> ISP Router -> 54321 -> Docker (54321) -> Plex (32400).

 

Historically, I had a different firewall in between the ISP Router and Docker which performed PAT, but I've removed that now and so want to ensure the traffic from the ISP router on TCP/UDP port 54321 gets to the Plex server on 32400.

 

Can someone help with this?

Try the Hotio's Plex docker, it's very easy to setup and I have not had any issues since I have installed it. In the template you can easly modify the external port by just changing its default value (32400) to whatever you want.

2 minutes ago, Holt said:

Try the Hotio's Plex docker, it's very easy to setup and I have not had any issues since I have installed it. In the template you can easly modify the external port by just changing its default value (32400) to whatever you want.

 

Thanks, issue is I would then have to set it all up again with Database etc wouldn't I? What option on the docker container did you change?

I just need to change the docker port from 32400 to 54321 I think. Is this sort of command even possible?

Either the port where this red arrow is, or the other side. 

 

Mapped ports don't do anything unless you are in bridge mode. Right now it's showing host, so port mapping is ignored, and all changes must be done in the app itself.

On 10/27/2023 at 5:46 PM, JonathanM said:

Mapped ports don't do anything unless you are in bridge mode. Right now it's showing host, so port mapping is ignored, and all changes must be done in the app itself.

Great, thanks for letting me know. Is there a way of doing what I need to in the app then? Changing the setting in the server settings doesn't seem to work. It puts it into indirect play mode which results in streaming 480p or less.

Why not use bridge mode?

24 minutes ago, JonathanM said:

Why not use bridge mode?

I don't understand it and I don't want to ruin the server. What would I have to do?

10 minutes ago, JonathanM said:

Is that it? Do I not need to do anything else?

Change the mapped port to what you want on the host side.

On 10/27/2023 at 6:46 PM, JonathanM said:

Mapped ports don't do anything unless you are in bridge mode. Right now it's showing host, so port mapping is ignored, and all changes must be done in the app itself.

Sorry, to respond on an older threat. But I believe above to be incorrect. I came across this threat while trying to solve a problem. My Plex docker being only reachable when setup in network type host. But once I change it to a custom network so it can communicate with a reverse proxy (Swag), I can no longer reach it unless via Tailscale setup in that reverse proxy. But not without Tailscale.

Looking at all the docker containers in use, I noticed that Plex doesn't have any ports mapped. Trying to solve this I found this thread and the comment above saying that port mappings don't do anything unless you are in bridge mode. Finally looking at official docker documentation on networks; https://docs.docker.com/engine/network/ I figured this was wrong. Doubting myselfI asked Grok AI for confirmation with the prompt/question: "Are docker containers running in a custom user-defined network reachable from the host's network without port mappings ?". The answer confirmed my understanding of the docker documentation; "Docker containers running in a custom user-defined network (e.g., a bridge network) are not directly reachable from the host's network without port mappings, unless specific configurations are made."

So I followed through. I added the port mapping for port TCP 32400 to the Plex docker. The server results were that the Plex client found the server in a second, no longer did it take 15 seconds. The Remote Access section of the Plex server now has a green check mark again saying; "Fully accessible outside your network." Before it was a red warning.

Using the IP address of the custom user-defined network I could not browse to the plex server yet. I had to add a static route on my Unifi router pointing the subnet towards the Unraid host. Once that was done I could use the custom user-defined docker network IP together with port 32400 to reach Plex web portal.

And Tailscale using the DNS record also works. I'm happy with the results, although it took some time troubleshooting it all.

@PatrickK

To be fair, what you just described is a whole separate can of worms than the standard: Host, Bridge, Container network setups.

Using Host mode, all ports the container uses are exposed to the host. Port mappings in the container template mean absolutely nothing.
All the original OP had to do was change his desired port in the plex network settings to whatever he wanted and then forward that at his router.

26 minutes ago, PatrickK said:

My Plex docker being only reachable when setup in network type host. But once I change it to a custom network so it can communicate with a reverse proxy (Swag), I can no longer reach it unless via Tailscale setup in that reverse proxy.

Custom networks require a special toggle enabled in the Unraid Docker settings "Enable Host to access Custom Networks: Yes" without this, you get no access from the host machine to those custom networks. For example services running on the host could not access custom docker networks. LAN access from external devices would not be affected.

Since the Reverse Proxy is on the Host it would have lost access to plex when plex was in a custom docker network.

docker and network related...
Some Docker networking Info when to use what docker network

what's your ip route for your ability to connect to the internet from the docker...

I would recommend running a generic bash docker to get docker terminal to ping and test a docker ability to get out to the internet.

@MowMdown

Thank you for your feedback. Reading through the entire thread again, I realize I opened whole separate can of worms like you said.

On 8/10/2025 at 2:18 AM, MowMdown said:

Custom networks require a special toggle enabled in the Unraid Docker settings "Enable Host to access Custom Networks: Yes" without this, you get no access from the host machine to those custom networks. For example services running on the host could not access custom docker networks. LAN access from external devices would not be affected.

I'm surprised that you recommended to enable "Host access to custom networks". Because earlier I came across a few posts in my search that mentioned not to enable this setting, posts claiming it would have no impact. I can't find them at the moment. Your advise makes sense, so I probably misunderstood it. Thank you.

Still, I'm glad that it forced me to think of another solution; adding the static route to my router. Because it enables access to the custom docker network from any device on my network (192.168.123.0/24), instead of (I assume) only the Unraid host getting access to the custom docker network when I would have enabled the setting "Host access to custom networks". I assume that only the Unraid host would have access to the custom docker network, because I never tested it. Below the screenshots to illustrate the above.

Static route within Unifi to custom docker network (172.19.0.0/24), named ProxyNet, pointing to Unraid host (192.168.123.10):

Browsing from another device within 192.168.123.0/24 to Plex via custom docker IP 172.19.0.2 on port 32400:

Browsing through Tailscale network via swag (wildcard certificate) and sub domain also works without specifying port:

On 8/10/2025 at 2:18 AM, MowMdown said:

Since the Reverse Proxy is on the Host it would have lost access to plex when plex was in a custom docker network.

The reverse proxy, swag, is in the same custom docker network as Plex. So swag can reach it by container name and IP.

Edited August 17, 2025Aug 17 by PatrickK