Comment by hdgvhicv

Nat 4, it’s trivial. But IPv6 tell me how terrible nat is despite it being the only solution in both the v6 and v4 world.

Sadly my 4g provider will not peer via bgp with me, even if I could provide an AS and Sufficiently large IP range.

I think my home ISP will actually peer with me, but I’d have to tunnel to them over my non-fibre connection, and there’s reduced resilience in that case.

At work that wouldn’t help at all, there are very few providers for many of our branch offices.

So once again ipv6 only works with “icky” nat, or on simple 1990s style connections, and not in the real world of multiple providers. Now sure I can do npt which means I don’t need to keep track of state, but then if I didn’t keep track of state I lose the benefits of a stateful firewall.

As such the only benefits of nat on v6 is that source ports will never need to change even if client 1 and client 2 both send to server 1 port 1234 from source port 5555. This helps with a handful of crappy protocols which embed the layer 4 data (port number) in a layer 6 or 7 protocol.