alt Hacker NewsWhy do you think NAT is part of a firewall? NAT and firewall are two completely separate things that can exist independently of each other.
Also overlapping ranges are an orthogonal issue that can occur with IPv6 private network range as well.
IPv6 brings not only bigger address range but also a big bag of other things that one cannot ignore, are complicated and which are often a source of problems. That's why people stick with IPv4 even at the cost of NAT, because the number of things they have to care about is much smaller.
> NAT and firewall are two completely separate things that can exist independently of each other.
This is kind of like saying that web browsers don't have to have a graphical interface. Or that a web browser doesn't necessarily support HTTPS. It's correct, but not practically correct.
The reality is that essentially all NAT software you'll actually encounter will be integrated into a stateful firewall because the two systems share so many functions that most projects and products that do one will also do the other. If you have a system with NAT set up and there is no packet filtering, it's most often because you've intentionally gone and disabled all the packet filtering, not because you need separate software for it.
It is important to understand that NAT doesn't have any inherent security to it, but criticizing people for talking like NAT is a feature built into firewalls when NAT is overwhelmingly a feature built into firewalls is a pretty unfair reading when we're talking about general deployments. Even with the technical audience of HN, we're not discussing carrier grade NAT here or other highly specialized or exceptional deployments.