Re:Reasons for servers to support IPv6
by franga2000 on Saturday January 29, 2022 @05:28PM
(#30131220)
> well, as long as there is a single machine that wants to listen on that port, at least
Well yes, most networks have more than one machine and multiple users might want to run the same service.
> you'll also need some kind of network address translation at the edge.
Not at all, each machine gets two addresses - one routable from the ISP and one non-routable from the router. Internal services simply use the non-routable ones.
And some kind of UPnP will still be required even if your internal network were using ISP-assigned IPv6 addresses for protocols that want to open multiple connections, like VoIP conferencing, bit torrent etc.
Of course, if you have an internal network where you actually communicate between your various machines, you won't want to use ISP-assigned publicly routable IPs, since those can change at any time, so you'll also need some kind of network address translation at the edge.