Why can I remotely access my PLEX server without port forwarding or UPnP

[dflachbart]

Server Version#:1.14.1.5488

I’m at my wit’s end, and maybe somebody can explain this to me:

I’m running my PLEX server on a Synology NAS, and used to have remote access enabled by port-forwarding 32000 in the router and allowing the port in the Synology’s firewall. Remote access worked fine, and in the PLEX server settings ‘Fully accessible outside your network’ showed green. A few months back I installed a new router (EdgeRouter X) and did not set up the port-forwarding again, and also removed the port from the Firewall configuration.

So here’s the weird part - yesterday I was traveling and was using the Wifi in the motel, and tried the PLEX app on my phone - and I was able to log in, see my library, and stream movies… How in the world is this possible?? The same when I disable WiFi on my phone and go through my carriers LTE, access to my server works fine… At home I double-checked that UPnP is NOT enabled on my router, also checked using ‘ShieldsUP’ that UPnP and port 32400 are stealth. PLEX server settings show ‘Not available outside of your network’ in red.

I’m just concerned that there could be some kind of security hole / misconfiguration in my network setup. Anyone able to explain this to me?

Thanks!
Dirk

[anon18523487]

Did you leave the remote access option enabled in PMS? If so, with that option enabled, Plex offers a feature called Relay, which routes the stream through Plex. So even if your network isn’t setup properly, you can still stream remotely. Disable remote access to turn this off as well.

[dflachbart]

Indeed, I just checked, I still had that enabled. Once I disable it connecting isn’t possible any longer. Thanks for the info, I didn’t know about ‘Relay’ (just read up about it here)!