Re: v6 subnet size for DSL & leased line customers

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.

> 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.
> 

On Mon, 31 Dec 2007 13:18:41 -0800
Joel Jaeggli <joeljabogus.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.
> > 
> 


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         alert."
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"Beyond Fear"