Is it possible to isolate Plex from reaching the internet (work only on LAN)?

[TeknoJunky]

[HowTo] Use Plex with No Internet

I’ve seen far too many posts regarding “can’t connect to Plex with no internet”, and an uprising/outcry always ensues. It eventually settles down, but the lack of single point resources can be frustrating. I’ve been there, no internet - can’t google anything from a computer so a phone will have to do, but navigating through results and trying “solutions” can be daunting. I’m creating this How-To to help alleviate those posts and help everyone access their servers when the net is down. Couple of …