Re: v6 subnet size for DSL & leased line customers

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

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.


> > 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"