[sclug] Who needs a /48?

[Dickon Hood]

On Wed, Apr 10, 2013 at 14:27:56 +0000, Ed Davies wrote:
: 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.

They'll have a /32 or bigger, but yes.

: 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?

The current addressing scheme of a /64 based on the MAC address works.  I
can't say it's what I'd've done, but it works, and works well; certainly I
have no trouble with it.

: 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.

/64's fine.

: Any advance on that?

Yes: /56 or /60.  Current best-practice is for a /56 for end users -- and
frankly I think that's overkill; most won't need more than a /64 with the
odd person wanting a /63 or /62 for partitioning reasons -- and larger
chunks for bigger customers.

I have a /48 on my ADSL and a /64 on my colo machines.  I use a /63 at
home, and the /64 on the colo.

Dickon Hood
-- 
Due to the release of iOS 6 Maps, my .signature is temporarily lost.  Normal
service will be resumed as soon as possible.  We apologise for the
inconvenience in the meantime.

This email was sent from a colocated server, and needs no excuses.