v6 subnet size for DSL & leased line customers
nanog at 85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org
Mon Dec 31 23:57:50 UTC 2007
On Mon, 31 Dec 2007 13:18:41 -0800
Joel Jaeggli <joelja at 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
> > 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
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