Dual stack IPv6 for IPv4 depletion

Thu Jul 9 01:57:43 UTC 2015

On 07/09/2015 02:38 AM, Mark Andrews wrote:
> A single /48 has enough space/subnets cover the entire infrastructure
> of 99.9999% of ISPs even using /64's for p2p links rather than taking
> one /64 and subdividing that for all of the p2p links. Treat the ISP
> as a business customer of itself when allocating address space for
> itself. A single /48 or one /48 per site. 

A single /48 is more than enough for infrastructure, yes. It was a
5-minute example. Bitmapping the allocations can't be done right now in
IPv4 (technically it can, but there's not enough to go around).

One of the good things about IPv6 is supposed to be not having to worry
about address waste. You're never going to fill up even a single /64
with current technology (you'll run out of MAC addresses first). Taking
the infrastructure example above: sure, a /48 is a waste. Who cares? So
is a /64 for my home network. Again, who cares? There are enough
addresses. As someone said here, they're just integers.

My whole point is: why not allow some room for more flexible
allocations? Compatibility was already broken by changing address length.

> The thinking is that ISP's are experts and can deal with managing
> complex allocation policy. They can also deal with multiple more
> specific routes etc. They already cope with this in IPv4. 

Uh... okay?