I have PMS running on a dedicated PC and have port forwarding on my router set up to forward 32400 to the ip address of that PC. All has been running well, I can access from outside of my network, share libraries, etc.
Now I’ve decided to try running PMS on my NAS (Western Digital My Cloud Mirror) and don’t know what to do with the ports. Right now all I’ve done is install PMS on the NAS, sign in, and set up one small library. At first I had the not accessible outside of your network message but that has gone away.
The remote access on my PC PMS is Private 192.168.1.110 : 32400 <- Public 12.34.5.678 : 32400 <- Internet
(32400 is forwarded manually through my router)
The remote access on my NAS PMS is Private 192.168.1.108 : 32400 <- Public 12.34.5.678 : 27646 <- Internet
Both my PC and my NAS have static internal ip addresses assigned by my router.
Should I forward an external port on my router to the internal port of my NAS?
@AngryDude said:
At first I had the not accessible outside of your network message but that has gone away.
Which means that the Plex server on the NAS has created a port forwarding for itself per UPnP.
with the result Private 192.168.1.108 : 32400 <- Public 12.34.5.678 : 27646
So you can just leave it at that.
Or you erase the automatic portforwarding and create a manual one after the same pattern:
internal: port 32400 → external: any other port (UPnP chose 27646, I’d use a similar one)
then (on the NAS Plex) go to Settings - Server - Remote Access and tick the check box
“Manually specify port” and put in the external port number you chose - Connect/Retry
see https://support.plex.tv/hc/en-us/articles/200931138-Troubleshooting-Remote-Access
scroll to “Manual Port Forwards for Multiple Servers”
You could leave it as is. The problem with that is uPnP is buggy at best. On most residential routers these uPnP ports are “cleared” every so often, so what works today might not work tomorrow. Most residential routers can’t be configured to turn this “feature” off. Depending on it to work correctly is a recipe for disaster. (OK, maybe not disaster, but don’t rely on it…) 
Otto has the right of it… Specifying the ports forwarded is a much more stable way to do it. Regardless of if uPnP gets cleared out on your router or not, the forwarded ports will ALWAYS be opened to the devices. Access to them will ALWAYS work, provided something on the network doesn’t change their circumstances.
I’ve been having a related issue for quite a while. I have two Plex Media Servers (PMS) but only one of them is visible to Plex clients via remote access. My original configuration had my primary PMS’s Remote Access to using the default automatic UPnP setting and the secondary PMS using manual port forwarding. Unfortunately, only the primary PMS was visible via remote access to Plex clients even though the secondary PMS was remotely reachable via a web browser.
The gist is: do not use automatic port forwarding on any PMS when you have multiple PMS sharing the same public IP address. Instead, port forwarding must be manually configured for both PMS to appear in the Plex cloud and be accessible to Plex clients via remote access.
Please read this carefully and consider the security implications of manually opening ports before proceeding:
- Log in to each PMS on the local network
- Make sure both PMS are logged in to your Plex cloud account
- Under each PMS’s Remote Access manually configure each to use different external ports (e.g. server1 - 29471, server2 - 29472)
- Log in to your edge router/firewall
- Create a TCP port forwarding rule for server1-ipadddress:32400 -> external-ipaddress:29471
- Create a TCP port forwarding rule for server2-ipadddress:32400 -> external-ipaddress:29472
- Launch the Plex client on a remote network (e.g. your smartphone or tablet over cellular with WiFi disabled)
- Log in to your Plex Cloud account on the remote Plex client and test playback from each PMS
