Re: v6 subnet size for DSL & leased line customers

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

On Tue, 1 Jan 2008 10:27:50 +1030
Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org> wrote:

> On Mon, 31 Dec 2007 13:18:41 -0800
> Joel Jaeggli <joelja () bogus com> wrote:
>
> > Mark Smith wrote:
> >
> > > Another idea would be to give each non-/48 customer the
> > > first /56 out of each /48. If you started out with a /30 or /31 RIR block , by
> > > the time you run out of /48s, you can either start using up the
> > > subsequent /56s out of the first /48, as it's likely that the first /56
> > > customer out of the /48 would have needed the /48 by that time.
> >
> > As stated, that approach has really negative implications for the number
> > of routes you carry in your IGP.
>
> Well, for 120K+ customers, I doubt you're using an IGP for anything
> much more than BGP loopbacks - and you'd have to be aggregating routes
> at a higher layer in your routing hierarchy anyway, to cope with 120K
> routes, regardless of what method you use to dole out /48s or /56s to
> end-sites.

It being New Year's Day and my brain not working right yet ... you'd
probably divide your RIR block up across your PoPs, and then could use
this technique within each PoP, with the PoP being the route aggregation
boundary. 
> > > Alternatively you might have become more comfortable with giving each
> > > customer a /48, and wouldn't require any of them to renumber - they'd
> > > just have to shorten their prefix length.
> > >
> > > Regards,
> > > Mark.
>
>
> -- 
>
>         "Sheep are slow and tasty, and therefore must remain constantly
>          alert."
>                                    - Bruce Schneier, "Beyond Fear"


-- 

        "Sheep are slow and tasty, and therefore must remain constantly
         alert."
                                   - Bruce Schneier, "Beyond Fear"