Re: v6 subnet size for DSL & leased line customers

[Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org>]

On Wed, 2 Jan 2008 00:42:59 -0500
"Christopher Morrow" <morrowc.lists () gmail com> wrote:

> On Jan 1, 2008 8:29 AM, Mark Smith
> <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org> wrote:
> > On Tue, 1 Jan 2008 12:57:17 +0100
> > Iljitsch van Beijnum <iljitsch () muada com> wrote:
> >
> > > On 31 dec 2007, at 1:24, Mark Smith wrote:
> > >
> > > > Another idea would be to give each non-/48 customer the
> > > > first /56 out of each /48.
> > >
> > > Right, so you combine the downsides of both approaches.
> > >
> > > It doesn't work when ARIN does it:
> >
> > Well, ARIN aren't running the Internet route tables. If they were, I'd
> > assume they'd force AS6453 to do the right thing and aggregate their
> > address space.
>
> 11920 - cogeco who I presume (just guessing) is doing this either
> because they have not aggregated by mistake or have to shed load and
> load-balance). I don't think teleglobe (6453) is at fault here...

Yeah, you're right, I missed the line wrapped AS_PATH.

> out of curiousity how is this sort of thing supposed to be done in v6?
> (traffic engineering given the '1 prefix per ISP' standard mantra)
>
> > > *  24.122.32.0/20   4.68.1.166               0             0 3356 6453
> > > 11290 i
> >
> > Static assignments of /56 to customers make sense to me, and that's the
> > assumption I've made when suggesting the addressing scheme I proposed.
> > Once you go static with /56s, you may as well make it easy for both
> > yourself and the customer to move to a /48 that encompasses the
> > original /56 (or configure the whole /48 for them from the outset).
>
> I think the assumption most folks make with DSL/cable is that
> end-users get dynamic assignments from a local (to the PE device)
> pool, similar to ipv4. I suppose you could do static assignments, but
> there's a management payment there that might not fit within the ISP's
> cost plan.  I presume that something accepting PD would be smart
> enough to let the end-hosts/lans know when their top 56 bits
> changed... and v6 includes auto-renumbering for 'free' right? So all
> solved?
>
> (yes some of that is joking... or at the very least pointing out a gotcha)
>
> -Chris


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