> If there are multiple routing nodes on the same link, coordination between the routers is required. For this the gnrc_ipv6_auto_subnets implements a simple UDP based synchronisation protocol where each router announces the number of subnets they want to create.
This is one benefit NAT has, you don't need coordination between routers. That's important in various business environments where you could have 2-3 or more levels of routers, each controlled by different entities. With NAT+DHCP you don't worry about how the public subnet can be divided up, each party just NATs and moves on.
> Unless you need inbound connections. Then you need coordination as well.
Right. In the cases I mention, inbound isn’t an issue. The various entities assume the worst for their routers (outbound only) and use VPNs where they control both sides. So no issues with DHCP-PD or insufficient subnet size allocation.
This is one benefit NAT has, you don't need coordination between routers. That's important in various business environments where you could have 2-3 or more levels of routers, each controlled by different entities. With NAT+DHCP you don't worry about how the public subnet can be divided up, each party just NATs and moves on.