I'm curious about something so I'm going to throw this thought experiment out here. For some background I run a pure IPv6 network and dove into v6 ignoring any v4 baggage so this is more of a devils advocate question than anything I genuinely believe.
Onto the question, why should I run a /64 subnet and waste all those addresses as opposed to running a /96 or even a /112?
- It breaks SLAAC and Android
let's assume I don't care for whatever reason and I'm content with DHCP, maybe android actually supports DHCP in this alternate universe
- It breaks RFC3306 aka Unicast-prefix-based multicast groups
No applications I care about are impacted by this breakage
- It violates the purity of the spec
I don't care
What advantages does running a /64 provide over smaller subnets? Especially subnets like a /96 where address count still far exceeds usage so filling subnets remains impossible.
We may replace it by then, but when people quote the 100 year thing like I have we sometimes forget to mention that is in reference to the current allocated 2000::/3 block.
We have several other blocks reserved for future use which will take several hundred years each to use up.
If we find a more efficient way of using address space then we can use those methods for the other /3 blocks.