Dual stack IPv6 for IPv4 depletion

Harald Koch chk at pobox.com
Thu Jul 9 16:01:11 UTC 2015


On 9 July 2015 at 11:42, Matthew Huff <mhuff at ox.com> wrote:

> What am I missing? Is it just the splitting on the sextet boundary that is
> an issue, or do people think people really need 64k subnets per household?
>

One thing you're missing is that some of these new-fangled uses for IP
networking will want to do their own subnetting. It's not "here's a subnet
for the car", it's "here's a /56 for the car to break into smaller pieces
as required".

A /56 isn't 256 subnets, it's 8 levels of subnetting (or 2 levels, if
you're human and want to subnet at nibble boundaries). A /48 is 16 (or 4)
levels. I have four vehicles, so I'd want to carve out a /52 for "the car
network" to make the routing and security easier to manage, and leave room
for expansion (or for my guests...)

One more consideration for you: we're currently allocating all IPv6
addresses out of 2000::/3. That's 1/8th of the space available. If we
discover we've messed up with this sparse address allocation idea, we have
7/8ths of the remaining space left to do something different.

-- 
Harald



More information about the NANOG mailing list