I’m using the latest version of Plex media server on my synology NAS, and on my iphone. My ISP is under nat so I don’t have a public IP (so i want to use the subnet ip and not the public ip detected by plex). The server is hosted by my parents (other network), and I reach the IP of the subnetwork from my house (Ping successful). From my network plex seems to work via web only and not via app (and not even on smart TV) even if i set the custom ip (the subnet one). Ideas? I attach pictures. Can I provide other data? Thank you!
You can’t address a subnet from the outside without knowing the public address. That compares to addressing an e-mail to „steve281188“ without a domain (could be @gmail.com, @aol.com, or pretty much anything)
Thank you for the reply!
Let me clarify this:
I’m using Fastweb as my ISP, which uses Carrier-Grade NAT (CGNAT). CGNAT is a method where multiple customers share a single public IP address, and the ISP assigns a private IP to devices within the customer’s network. This means that, while my devices are able to communicate within the private network, they don’t have a unique public IP address assigned directly to them.
This is why I don’t have a public IP address for my home network, but rather a private subnet IP. While this setup allows me to connect to devices within my network (like my Plex server hosted at my parents’ house), it creates limitations when trying to connect to external services or when devices are on different subnets.
I have a Plex server installed on my Synology NAS at my parents’ house, which is also on a private subnet (e.g., 192.168.x.x). I can ping the router of their network from my home, indicating that the network is reachable via NAT, but despite that, I’m unable to connect to Plex via the app.
The web version of Plex works fine, and I can access the server through my browser. However, when I manually set the same IP address (the one that works through the web interface) in the server settings of both the Plex iOS app and the Samsung TV app, it still doesn’t connect.
I’m wondering why the web version works, but the Plex app on iOS and Samsung TV doesn’t connect to the server. Could this be due to the CGNAT settings, or is there something in the network configuration I’m missing that might be blocking the connection for the app?
Based on the setup described above, I don’t have access to the “main router,” and it’s not possible to expose Plex to the outside beyond that router.
Thanks for any insights!
You could try specifying the subnets under the LAN Networks in the network settings on your PMS. Note subnets need to be specified as common subnet masks rather than CDIR (e.g. 255.255.255.0 rather than \24.
Another option is to use a Custom Server URL under the Network Settings. You’ll need to use the plex.direct URL format. So if their WAN IP is 192.168.0.4 then the custom URL would be in the format https://192-168-0-4.xxxx.plex.direct:32400 where xxxx is the hexadecimal prefix applied to the server’s SSL certificate. I would also suggest turning off remote access so only the local and custom URL are published upstream to Plex.TV (remote access setting just tells Plex to publish it’s WAN IP, and provided there is a port forward in place it can still be accessed).
If I may?
-
Using the
plex.directURL is always short lived. Each time your certificate renews, you will get a new hashcode in the URL. It is meant for PMS/Plex-internal use only (they update this info every time they start) -
CGNAT serves the ISP.
-
CGNAT is a convenient way to control the outbound traffic.
-
CGNAT means your WAN IP isn’t a real IP. It doesn’t exist on the open internet because it’s shared, randomly, with many other users.
-
CGNAT prevents running servers like Plex or any other streaming applications.
Some ISPs allow you to buy a real IP address for a monthly fee.
If not, your only predictably viable alternative is to use a VPN with a DDNS-updated endpoint and external DNS which tracks that exit IP addres.
SOLVED!
How to Make Plex Apps Reach the Server When the Public IP Detected by Plex Is Incorrect
If your Plex web app (eg. http://[Subnet IP]:32400) works but mobile and Smart TV apps fail to connect, the issue may stem from CG-NAT (Carrier-Grade NAT) implemented by your ISP. This guide will help you configure Plex so that devices within your local or shared subnet can connect to the server, even when the public IP detected by Plex is incorrect.
Step 1: Verify Subnet Accessibility
The solution requires that your devices (e.g., mobile/TV) can connect to the private subnet IP of the router managing the subnet where the Plex server is hosted. Here’s how to confirm:
1. Understand “Subnet IP”:
• The subnet IP is the private IP assigned to your router by the ISP (e.g., 100.64.x.x) and is different from a public IP, which you lack under CG-NAT.
• To find the subnet IP, log into the router managing the subnet where the Plex server is hosted:
• Access the router interface by entering its local IP in a browser (e.g., 192.168.x.x).
• Look for the WAN IP or Internet IP in the router’s settings. This is the subnet IP assigned by your ISP.
2. Test Connectivity from the Accessing Network:
• From the network where you want to access Plex, open a terminal or command prompt and ping the subnet IP of the router:
ping [Subnet IP]
Example::
ping 100.64.1.10
If the ping succeeds, the accessing network and the server’s network are in the same subnet, and you can proceed.
Step 2: Forward Plex Ports on the Router Managing the Subnet
To allow devices within the subnet to access the Plex server:
1. Access the router managing the subnet and go to the Port Forwarding settings.
2. Forward the following port to the local IP of the machine hosting the Plex Media Server:
• Port 32400 (default Plex port).
3. Save the changes and restart the router if necessary.
Step 3: Configure an Alternative Subnet URL in Plex
1. Open the Plex web app by navigating to http://localhost:32400 or entering the server’s local IP in a browser.
2. Go to Settings (wrench icon) > Network.
3. Locate the Custom server access URLs field.
4. Enter the URL using the subnet IP:
http://[Subnet IP]:32400
Example:
- Save the settings.
Step 4: Test Connectivity
1. Restart the Plex Media Server.
2. Open the Plex app on your mobile device or Smart TV and try connecting to the server:
• Ensure your device is connected to the same shared subnet (e.g., via Wi-Fi or LAN).
Key Notes
1. Subnet Accessibility Only: This solution works only within the shared subnet. You cannot access the Plex server from outside the subnet without a public IP.
2. Subnet IP vs. Public IP:
• The subnet IP is the private IP assigned to the router by your ISP and can be found in the router’s WAN settings.
• Avoid using external services like “What is my IP” websites, as they will show the public-facing IP (not relevant under CG-NAT).
3. No Remote Access: Since CG-NAT blocks public IPs, you won’t be able to access the server remotely over the internet. This workaround works only for local access.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
