Plex doesn’t route anything, your router is doing the port forwarding.
What port? The only port that should ever be showing as open on the PC is 32400.
Hi @Krazeh - The port is a port other than 32400 being assigned in the ‘Remote Access’ portion of the Plex application, in the field that states '‘Manually Specify Public Port’.
My specific question is to ask - when a person enters a port in the ‘Manually Specify Public Port’ field in Plex and clicks on the ‘Apply’ button within the Plex Remote access screen and it shows a circle animation and ‘Connecting Server’ - what specifically is being triggered in the Plex process? I’ve opened Task Manager to review and it’s not clear.
In several other threads here in the Plex forum, people are able to use something other than 32400 in this port field.
If it helps at all, I can attach a video if needed that shows these same custom ports are accessible and open when using other programs. My intent with my question is to get more understanding of what is specifically happening when that ‘Apply’ button is pressed in Remote Access for the custom port, and what more to review to resolve.
Internally, i.e. on the pc running Plex, the only port you need to worry about is 32400. Plex always listens on that port.
When you put a different port for remote access it updates the external address for clients to use, but that’s it. It doesn’t change the actual port that your Plex server is listening on, that always stays as 32400. That’s why you’re router needs to be set up to forward any connections it recieves on your custom port to port 32400 on the device running Plex.
Yes that portion is understood. I believe I did respond previously in multiple posts with my screenshots and setup. I do show the router configuration both when using AT&T router alone, and also when using a secondary router in IP passthrough with UPnP enabled, and the routing rules in Port Forwarding for each.
Is there something more I can review from Plex logs when that ‘Apply’ is pressed in Remote Access to get a better understanding? @Krazeh are you a plex support employee or another user here? I wasn’t sure how to tell from the username and titles next to them.
My thoughts are to review more logs, and possibly run a har file in Chrome to review when Apply is called. Also to possibly run a fiddler trace to see if I can get more info. Was hoping a Plex Support employee could chime in here to give a pointer or two for logs and the process, but if this isn’t the right place for that would appreciate any tips on how to reach someone to ask.
So what port are you listening to when using this piece of software? 32400 or the custom port you’ve selected?
For the port it is any one of multiple within 20k to 50k range, those ports are on the thread in previous replies. 32400 has always been open for me with Plex installed. I can also access 32400 with the port listener, well assuming Plex isn’t running in my browser at the time.
If you had the rules set up correctly then the listening software shouldn’t be showing the custom port as being open. Those ports should not be reachable inside your network.
How many port forward rules do you currently have set up for Plex?
Not sure what you are meaning, but on this side I have Windows Firewall rules for any of the custom ports I’ve added (I’ve tried four different). Also have rules in my router Port Forwarding for the ports.
When Plex Server is running and I use an open port checker online, it shows as open on port 32400. Are you stating that 32400 shouldn’t be showing as open on that port when checking using Open Port Check Tool - Test Port Forwarding on Your Router ? Because that is what Plex is using and that works, and is open.
My references to using Port Listener from RJL software were to test if one of the custom ports I am assigning are able to show as open when that program is running. You can check the page for the definition of what it does. When that is running and I have a port assigned and check with Open Port Check Tool - Test Port Forwarding on Your Router it shows as open. That is what I would expect Plex would be doing when I enter the custom port in Remote Access, but it’s not. If I’ve missed anything in the explanation or something is not provided let me know and I can relay more information.
When you only provide half details it’s really difficult to understand what exactly it is you’ve done or are testing. With things like this it’s really important to be specific and as detailed as possible.
Having said that, what might assist here is an illustrative example:
Let’s assume your Plex server is set up on a device with the IP 192.168.0.10. Let’s also assume your ISP gives you an external public IP address of 10.1.1.1.
When you setup your server and sign in, it goes and tells Plex’s systems that you have a server and that it is available locally at 192.168.0.10:32400 and (if you have turned on remote access) remotely at 10.1.1.1:32400. Then when you use a client app they go to Plex and ask where the server is. They get provided with these addresses and try to connect (I believe they try locally first and then remotely, but for this example it doesn’t really matter).
For the remote access to work you need to set up port forwarding on your router (or use UPnP) to forward connections received at 10.1.1.1:32400 to 192.168.0.10:32400.
If you later decide you want to use a custom port (say 32687) for remote access your server tells Plex’s systems that it’s now available remotely at 10.1.1.1:32687. However, the internal address stays as 192.168.0.10:32400. That never changes.
To get this new remote access working you have to change the previous port forwarding rule so that connections to 10.1.1.1:32687 get forwarded to 192.168.0.10:32400.
If you are ever trying to check if your port forward is working then whatever piece of software you are running on the same device as you’ll be using for Plex needs to be listening on 32400, no matter what external port you are checking.
At the moment it’s really not clear if you are using Port Listener to listen to port 32400 when testing, or if you are listening to the ‘custom’ port (e.g. 32687). If it’s the former and doing an external check to the custom port shows as open then Plex should be working. If it’s the latter and it’s showing as open then your port forwarding rule is wrong.
1 Like
EDIT: What @Krazeh says. Was typing my reply at same time. 
Port Forwarding
Plex Media Server always uses port 32400 to communicate with clients, whether local or remote.
If you wish to use a different port externally, you must modify the port forwarding rule in your router.
The router will then re-map traffic to port 32400 and send it to the Plex Media Server.
The open port on Plex Media Server remains 32400. The external port will never show as open on the Plex Server (unless it is 32400).
If you use an external port check, such as canyouseeme.org, it will show whether the external port is open (PMS must be running when checked).
Manually Specify Public Port Checkbox
Not checked: Plex uses UPnP to try and open a port on the router.
Checked: Plex uses the port forward statement in the router.
Manually entering the port number in Settings → Remote Access
This tells servers at plex.tv which external port you are using. They then send that info to any remote apps streaming from your server.
The remote Plex app does not initially know the IP address or port number of your server.
When a remote user launches the app and logs in, the app communicates with servers at plex.tv.
The plex.tv hosts verify their login, and which servers they can access.
It also tells the app the public IP address of the Plex Media Server and which port to use to communicate with the Plex Media Server.
The Plex app then communicates directly with the Plex Media Server.
Tying it all together
A remote user launches the Plex app and logs in to their account.
Servers at plex.tv verify their login. They also tell the app, “You can access to snarble33’s server. Contact it at IP address X using port Y.”
The Plex app sends a request to the Plex Media Server at IP address X using port Y.
Your Internet router sees the request. Using the port forwarding rule, it remaps the port from Y to 32400, then forwards the request to your Plex Media Server
Plex Media Server then sends the info to the remote Plex app.
1 Like
I had a full day at the hospital for a family visit yesterday and wasn’t able to get to this until late morn/early afternoon today.
After reviewing and re-checking everything based on the last responses, still nothing worked. I then disconnected the secondary router and reset my AT&T router to default, reconfigured the forwarding rules and IP allocation etc and still no luck.
Out of frustration I decided to do a full reset and reinstall of Windows 11 on the PC in question. I got all my core apps and programs installed and configured and installed Plex Server again, then added my local firewall rules and re-added my port forwarding rules in the router. And… it just works now.
I wish I would have stayed with the issue on the previous install environment to understand what in the #### was happening, and neatly wrap this thread up with a resolution specific to the original problem. It was just too upsetting to deal with for that amount of time and apparently a fresh install and start cleared up whatever was causing this to break.
To sum up - added the port forwarding rules in my AT&T router for the custom port, with a base port of 32400 (same as it was in my other install). Rules added to my firewall for those two ports using TCP on incoming and outgoing (no change to this either). Custom port assigned in Remote Access and it just works now.
One extra layer I wanted to try was to access Plex remotely when my VPN is active on the Plex Server - AirVPN allows port forwarding with their VPN. And this also works. I’m pleased at the moment this is resolved, but still frustrated that I couldn’t determine what was wrong in the other environment and that I poured a boatload of hours into it.
Anyways thanks to @FordGuy61 and @Krazeh for the responses here.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
