[clug] IPv6 for home

Francis James Whittle fj.whittle at gmail.com
Sun Jan 1 00:15:32 MST 2012

On Sun, 2012-01-01 at 16:25 +1100, Scott Ferguson wrote:
> Is that a serious question? I'm pretty sure the post had my name in it ;-)

Eh, backtracking, I'm too lazy.

> > IPv6 is pretty simple to set up as soon as you throw of the shackles
> > holding your mind to IPv4,
> Which is what I basically said.

Well, yes, but:

> > regardless of the number of devices.
> My apologies for confusing you, I was specifically responding to Mikal's
> post - substitute 16 for any number to large to easily add as entries
> into hosts for intranet DNS.  (IPV8 => 16 devices, logical really)

I think the hosts file on any given desktop here contains localhost and
the hosts' own fqdn.  I also have the external IPv4 address for
convenience's sake when making traceroutes.  I use Avahi almost
exclusively for local DNS.
It would be interesting to know if multicast DNS is any good at large
numbers (let's say 10000 or so) of hosts... Sadly the only way I would
have of testing this would be to boot up a large number of virtual
machines, and I'd probably run into memory usage problems even if I had
a series of images that did nothing but boot up and launch an mdns

> > For example, I could just plug up to around 2^64 devices into my
> > network 
> > and... well I wouldn't be able to power them all, but you see
> > how that's 32 times the ENTIRE ipv4 address space, and I still
> > shouldn't have run in any major configuration problems (Except the
> > problem of where to put so much stuff, and how to power it).  After
> > that point I have another 255 networks of the same size to plug stuff
> > into, because my ISP handed me an unreasonably large block of
> > addresses.  Seriously, what could I possibly need a /56 subnet for?
> Interesting - unfortunately my brain refuses to do big math today....
> like projected population size and uniquely identifiable network
> connected devices.
> Is it possible that the IPV6 address pool is large enough for mandatory
> hard-coded addresses in devices instead of SA[*1]?

I worry about the routability of mandatory hard coded addresses....

> Perhaps I just haven't considered the number of possible discrete
> networked devices of the future...?

It's physically improbable to ever have that many things.  I'm talking
about individuals filling up their /64.

> Or maybe your ISP just decided that, as they had so many addresses they
> could take the easy option of sub-netting their /32 into /56s, instead
> of the smaller /48s (as originally planned).

True.  If the size prefix they hand out is ridiculous, it's only
because they have a ludicrous number of ridiculously sized prefixes to

> Cheers
> [*1] in line with Cory Doctrow's suggested possible future computing devices

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