In non-abstract terms, I just don’t see how that works better.
In non-abstract terms, I just don’t see how that works better.
Because you do not know ahead of time which devices may have such a need, and by allowing for the possibility you open up more flexibility.
> [Residential customers] don't care about engineering, but they sure do create support tickets about broken P2P applications, such as Xbox/PS gaming applications, broken VoIP in gaming lobbies, failure of SIP client to punch through etc. All these problems don't exist on native routed (and static) IPv6.
> In order for P2P to work as close as possible to routed IPv6 in NATted IPv4, we had to deploy a bunch of workarounds such as EIM-NAT to allow TCP/UDP P2P punching to work both ways, we had to allow hairpinning on the CGNAT device to allow intra-CGNAT traffic to work between to CGNAT clients, as TURN can only detect the public-facing IP:Port, hairpinning allow 100.64.0.0/10 clients to talk to each other over the CGNATted public IP:Port.
* https://blog.ipspace.net/2025/03/response-end-to-end-connect...
By having (a) a public address, and (b) a CPE that supports PCP/IGD hole punching, you eliminate a whole swath of infrastructure (ICE/TURN/etc) and kludges.
When it was first released, Skype was peer-to-peer, but because of NAT "super nodes" had to be invented in their architecture so that the clients/peers could have someone to 'bounce' off of to connect. But because of the prevalence of NAT, central servers are now the norm.
A lot of folks on HN complain about centralization and concentration on the Internet, but how can it be otherwise when folks push back against technologies that would allow more peer-to-peer architectures?
It doesn't help.
When internet finally became popular, hosting a website on your own machine already became infeasible.
These days ISP can’t get hold of new IPv4 blocks, and increasingly don’t provide public IP addresses to residential routers, not without having to pay extra for that lowly single IPv4 address.
Hosting a website behind a NAT isn’t as trivial as it used to be, and for many it’s now impossible without IPv6.
It's impossible with ipv6 either. ISPs block incoming connections on ipv6 for residential addresses.
The example I keep coming back to is multiplayer games like Mario Kart, where Nintendo tell you to put the Switch in the DMZ or forward a huge range of ports (1024-65535!) to it [1].
If you’ve got more than one Switch in the household, though, then I guess it sucks to be you.
1: https://www.nintendo.com/en-gb/Support/Troubleshooting/How-t...
So yes, if you disable the requisite, standard, built-in feature on your router, you may need a pretty annoying workaround. Weird!
What percentage of users do you imagine disable upnp? Let’s be real. This is a problem that your average user will never, ever experience a problem with.
I'm sure the Switch deals with conflict resolution with multiple consoles on the same network too but shrug it's another example of how NAT is a pain and also contradicts your assertion that incoming connections would be a breach of ISP ToS [1].
Edit: A quick Google suggests the Switch originally didn't support UPnP, and the Switch 2 now supports IPv6.
The reason Google bought and destroyed dejanews.com, for example (try visiting that site) was to weaken one of the distributed sources of competition. Similar for RSS.
The problem is that flexibility is often the enemy of security, and that’s certainly true here. Corporate networks don’t want to allow even the possibility of devices that are supposed to be private being publicly addressable. Arguing that it’s “simpler” or “more flexible” is like arguing that we don’t need firewalls, for the same reasons. And in fact, that argument used to be made quite regularly. It’s just that no-one who deals with security has ever taken it seriously.