nanog mailing list archives

Re: Dual stack IPv6 for IPv4 depletion


From: "Israel G. Lugo" <israel.lugo () lugosys com>
Date: Thu, 09 Jul 2015 02:57:43 +0100


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?


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