[ppml] Solicing comments: IPv4 to IPv6 Migration IncentiveAddress Space

William Herrin arin-contact at dirtside.com
Wed Jun 27 11:49:59 EDT 2007

On 6/27/07, Jeroen Massar <jeroen at unfix.org> wrote:
> William Herrin wrote:
> > The question was: how would this proposal impact the routing table. In
> > the worst case scenario, this proposal would place the same number of
> > routes in the IPv6 table that are presently in the IPv4 table: roughly
> > 220,000.
> No, you are looking at it from the wrong way. At the moment there are
> about 40k active ASN's who indeed announce about 200k IPv4 routes.
> In IPv6 there are about 1000 prefixes (of which ~800 good ones) in the
> IPv6 tables, with about 800 ASN's announcing them. That is a ~13%
> overhead. Thus if every internet-active ASN would announce a single
> prefix + the overhead you would get 40k + 13.3% is only ~55k prefixes.


That sounds like its closer to the best case scenario: every IPv4 org
deploys IPv6 but    the orgs with large numbers of v4 allocations
choose not to claim them under this proposal and get single
allocations through the regular process instead.

> You are wrong again though, routers need to handle the FULL 128bits. And
> fortunately currently they still do that.

Okay. Then my original numbers for the worst case stand: each IPv6
route slot takes roughly 4 times the memory of the IPv4 route slots
and the worst case is that we have the same number of them as we do
IPv4 slots.

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

More information about the ARIN-PPML mailing list