[sclug] Who needs a /48?

[Ed Davies]

On 2013-04-07 19:47, Keith Edmunds wrote:
> Well, if you choose to use BT as your ISP... Seriously, I wouldn't. In my
> experience, the smaller ISPs are way, way better. I'm now with Andrews and
> Arnold, and would recommend them (they're not as expensive as I thought
> they would be, and they are good).

Interesting. I see that A&A offer /48 addresses. Space is big, etc,
but still this seems a bit wasteful. We've, in effect, run out of
IPv4 /32 addresses. 65536 (minus a few) times is a lot more but there
are a lot of bods on the planet, too.

By the time you've dropped a few bits off the front for different
addressing schemes that only leave a few hundred addresses for each
of the 10 billion or so people likely at peak peeps - a small enough
number that some sort of careful management would be required.

I can just about see the argument for a /80 address. It allows you
32 bits to route any existing IPv4 addresses you are using plus
another 16 bits to fence those off and route anything IPv6 you have.
Why would anybody want any more?

Thinking out loud, you could make the same argument for 48 bit MAC
addresses being used for link-local plus 16 bits for further
disambiguation needing 64 bits, so /64.

Any advance on that?