I've been running Plex on my Synology DS-412+ for a couple of years now, have the lifetime Plex Pass, and have never had any real trouble with remote access. Some time over the last couple/few weeks, though, it has stopped working. I'm running 1.1.3.2700-6f64a8d and Plex Remote Access settings say:
> Your server is signed in to Plex, but is not reachable from outside your network.
The server mapping in the Plex settings says that my ISP's public IP at port 32400 is mapped correctly to the internal IP address for the Synology NAS at the same port. But then there's a red "X" next to Internet and the text explaining that it can't be seen from the internet.
My router, an ASUS RT-AC68U has latest firmware, and UPnP enabled, and I have manually entered the port forwarding for port 32400 to the NAS. The firewall on the NAS is set to allow traffic on 32400 as well.
When I go to [1] and enter 32400 for my IP, it says "Success". I've also gone through all the steps at [2] and [3]. I have only my own cable modem (Comcast) and then the router, so I'm not dealing with double-NAT and have never enabled jumbo frames. The NAS is at a static internal IP on the network and the Plex settings are set to manually specify 32400 as the port. Client devices in the network, including AppleTV, various iOS devices, and a Samsung SmartTV seem to have no trouble accessing the Plex content.
I've re-started the NAS and router both (more than once) and restarted the Plex service on it numerous times. The only difference in behavior I see when restarting is that when I enabled remote access, it will show the green remote-access-enabled message for 3-5 seconds before it turns red and returns to "not available outside your network".
I'm at a loss as to what to try next but would love to resolve this before some upcoming travel. Thanks in advance for any suggestions.
- J
[2] http://portforward.com/english/routers/port_forwarding/Asus/RT-AC68U/Plex_Media_Server.htm
[3] https://support.plex.tv/hc/en-us/articles/200931138-Troubleshooting-Remote-Access