filtering /48 is going to be necessary

PC paul4004 at
Fri Mar 9 10:04:56 CST 2012

I think ARIN issues /48s for Provider independent space as the minimum
allocation size, so I'm guessing we shouldn't filter below that.  At least,
that's what's in their current policies.

On Fri, Mar 9, 2012 at 7:50 AM, Bernhard Schmidt <berni at>wrote:

> Jeff Wheeler <jsw at> wrote:
> Hello Jeff,
> > On Fri, Mar 9, 2012 at 3:23 AM, Mehmet Akcin <mehmet at> wrote:
> >> if you know anyone who is filtering /48 , you can start telling them
> >> to STOP doing so as a good citizen of internet6.
> >
> > I had a bit of off-list discussion about this topic, and I was not
> > going to bring it up today on-list, but since the other point of view
> > is already there, I may as well.
> >
> > Unless you are going to pay the bill for my clients to upgrade their
> > 3BXL/3CXL systems (and similar) to XXL and then XXXL, I think we need
> > to do two things before IPv6 up-take is really broad:
> >
> > 1) absolutely must drop /48 de-aggregates from ISP blocks
> > 2) absolutely must make RIR policy so orgs can get /48s for
> > anycasting, and whatever other purposes
> I used to be (or still am) on the same page as you are. I was dropping
> everything smaller than a /36 from PA ranges at the edge.
> I recently had to relax this filter, because Cloudflare seems to insist
> on throwing tons of /48s from their 2400:cb00::/32 into the air without
> an aggregate. And guess what the popular cloud reverse proxy for IPv6
> webpages is these days ... cloudflare.
> Yes, it sucks, yes, I wrote them, but no answer and no change.
> Best Regards,
> Bernhard

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