[ppml] Legacy /24s

William Herrin arin-contact at dirtside.com
Mon Sep 3 10:27:14 EDT 2007

On 9/3/07, Owen DeLong <owen at delong.com> wrote:
> Most internet-oriented technology needs to be refreshed on a 2-4 year
> life-cycle, actually.

I generally get better results from my equipment buy YMMV.

> > The number of routes and ASes in the DFZ implies that there are
> > somewhere between 200,000 and 300,000 routers in the DFZ.
> >
> Here, I think you go off the rails with a big hand-wave.  How, exactly
> do you think you can correlate the routes+ASs in the DFZ to the
> number of routers participating in the DFZ?

As I said before, its a SWAG. Some of the better educated responders
suggest that I'm around 50k too high here with the actual number in
the 150k-250k range.

> Why is an IPv6 prefix 2x an IPv4 prefix?

That's what Cisco is claiming in their documentation. 1M IPv4 routes
or 500k IPv6 routes. I assume this probably means they're stashing the
first 64 bits into the TCAM and bouncing it up to the software if you
need a route more specific than /64. Sounds sloppy to me but I'm not

> > So, with any proposal to expand the availability of IPv6 PI, the
> > question that should be asked is: "Does the proposed use in the
> > expansion justify asking the rest of the world to pay $17k?"
> Since that's 17k divided amongst 30k or so organizations, you're
> really asking each other org. to foot a $0.50 bill per prefix.

26109 AS's according to the latest routing table report yielding
closer to $0.65. But that's a false way of looking at problem. Some
AS's have one DFZ router. Some have many. None interact with the
problem in terms of individual routes; they have to deal with the
whole route count.

Looking at the cost of an individual route is useful in terms of the
whole systemic cost accross the entire DFZ.

> > My opinion is that in the case of a multihomed content provider, the
> > answer is yes. Why should he receive poor treatment in IPv6 merely
> What about a multihomed content consumer?  Why should they
> be treated any worse than a multihomed content provider?

Because non-PI multihoming solutions for the NATed content consumer
are relatively trivial to build.

> Nobody really cares about the $100/yr.  Proposals to waive that
> have been targeted at providing what little incentive we can towards
> other behaviors for the common good.

Yet the original posters in this thread brought it up as a complaint.

Bill Herrin

William D. Herrin                  herrin at dirtside.com  bill at herrin.us
3005 Crane Dr.                        Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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