Re: Is a /48 still the smallest thing you can route independently?

[Owen DeLong <owen () delong com>]

On Oct 11, 2012, at 2:17 PM, Jeroen Massar <jeroen () unfix org> wrote:

> On 2012-10-11 23:02 , Jo Rhett wrote:
> > I've finally convinced $DAYJOB to deploy IPv6.  Justification for the
> > IP space is easy, however the truth is that a /64 is more than we
> > need in all locations. However the last I heard was that you can't
> > effectively announce anything smaller than a /48.  Is this still
> > true?
> >
> > Is this likely to change in the immediate future, or do I need to ask
> > for a /44?
>
> A /64 is for a single link (broadcast domain, though with IPv6 multicast
> domain is more appropriate).
>
> A /48 (or /56 for end-users for some of the RIRs) is for a single
> end-site ("a different administrative domain and/or a different physical
> location").
>
> If you thus have 5 end-sites, you should have room for 5 /48s and thus a
> /47 is what you can justify.
Couple of errors there, Jeroen…

1. 5 /48s is at least a /45, not a /47 which is only 2 /48s.

2. Joe lives in the ARIN region where allocations and assignments are
        done on nibble boundaries, so his /45 would be rounded up to
        a /44 (as would a /47) anyway.

Owen