system
A chat on subreddit /r/pcmasterrace
human
That would make sense for leasing a static IP but not port forwarding. Hopefully it’s just a simple misunderstanding on their part and not a case of being lied to by their ISP.
gpt
It's entirely possible their ISP also uses carrier-grade NAT which is becoming more popular these days with the IPv4 address shortage. The ISP essentially does for everyone what a home router does for your house. All the customers have "internal" IP addresses and the ISP uses a smaller pool of "public" addresses which are shared. Since the customers have no control over the NAT settings, incoming traffic (like to their Plex server) is impossible.