+1

see also:
viewtopic.php?t=110925
viewtopic.php?t=42614
viewtopic.php?t=94291

Internet-Uplinks going IPv6 only. Small IoT devices stick to IPv4.

+1 for NAT64. I can live with DNS64 on the powerdns recursor

Couldn't you run Jool in Docker now?

• Movement to NAT64 is clear as Apple has had requirement for this since 2018 for all apps. No need for more complex solutions, these can come later.
• It would help much for re-architecting networks as IPv6 becomes mandatory in different countries.
• It would make it possible to create and manage IPv6-only networks and save from double work of managing dual-stack.
• AWS also recently made big enhancements to it's products to enable IPv6-only networks and services and also added NAT64 functionality to it's gateways.
• As Mikrotik currently supports only DHCPv6-PD and SLAAC, some solution is needed for more meaningful IPv6 DNS-management.
• DNS64 service is already available from CloudFlare and Google, no hurry with this.

i'm looking for something simple, example:

iptables -t nat -A PREROUTING -d <ipv4> -j DNAT <ipv6>
iptables -t nat -A POSTROUTING -s <ipv6> -j SNAT <ipv4>

IPv6 NAT is NAT66 and should be avoided completely. The point of IPv6 is to restore end-to-end principle.

NAT64 and it's better sibling 464xlat are not the same thing as NAT66 aka IPv6 killer:
https://blog.apnic.net/2018/02/02/nat66-good-bad-ugly/

Some people must've learnt network engineering from the trash can... Smh

i'm looking for something simple, example:

iptables -t nat -A PREROUTING -d <ipv4> -j DNAT <ipv6>
iptables -t nat -A POSTROUTING -s <ipv6> -j SNAT <ipv4>

For what it's worth, when you translate between IP versions, then both source and destination address have to be translated in some way (usually in the same rule). IE if have a packet coming from 2001:db8:aa::1 -> 2001:db8:ff::1 port 80 and I want that to be translated to go to -> 192.0.2.1 port 80, then what should my source address be? The original source IPv6 address can't be used.

It's more complicated than just adding another translation. Especially when you look at different strategies for doing the translation. Going from IPv4 to IPv6 gives you the chance to do it in an entirely stateless way as long as you don't expect the IPv4 world to be able to address the entire IPv6 world, but only a small /96 chunk of it.

ipspace.net has a presentation on an ipv6 only datacenter design that uses this. In most other cases you can't do nat64 or nat46 in an entirely stateless way.

I guess my point is that in this thread people are asking for a number of different solutions. Sometimes the use case presented is clear and sometimes it's not. What kind of network design does a feature like this enable for you? It's easier for the developers if they have a strong use case.

I think pretty much everyone here has a good use case, but some need a more clear description of what they'll get out of their network by having a specific feature.