> Can you convince me that end-to-end connectivity is desirable in most cases? I certainly don't want ingress from the public Internet to devices on my home net

> Can you convince me that end-to-end connectivity is desirable in most cases? I certainly don't want ingress from the public Internet to devices on my home network in the general case […] In the IPv4 case you have NAT and a firewall. If you have some software that you want others to connect to (communication, gaming, etc) you have to punch a whole through the firewall (via UPnP, PCP) and then the software has to use a bunch of protocols to figure out what the public IP address of your router is: see STUN, TURN, etc. See "How NAT traversal works": * https://tailscale.com/blog/how-nat-traversal-works/ https://tailscale.com/blog/how-nat-traversal-works/ * https://news.ycombinator.com/item?id=30707711 https://news.ycombinator.com/item?id=30707711 (2022) * https://news.ycombinator.com/item?id=24241105 https://news.ycombinator.com/item?id=24241105 (2020) With IPv6 you just have a firewall, which you punch a hole through when needed (UPnP, PCP) and you're done (because there's no futzing about with determining the network address). When the P2P session is done the whole is closed and you're protected again. So if you have a 'home network', it cannot be reached from the Internet by default. Note: you already have a device that's always on the Internet: your mobile phone. Lots of telcos are IPv6-only and you there's not NAT or firewall between it and the Internet.