The Choice: IPv4 Exhaustion or Transition to IPv6

Stephen Sprunk stephen at
Thu Jun 28 23:15:29 UTC 2007

Thus spake "Iljitsch van Beijnum" <iljitsch at>
> The Comcasts of this world burn addresses by the millions. If they  can't 
> have new ones for (almost) free, they'll have to stick multiple  customers 
> behind a single IPv4 address. If you have to share your IP  address with 
> several of your neighbors, it becomes attractive to add  IPv6 to the mix 
> to make peer to peer stuff, including VoIP, work more  reliably. QED.

More likely, one day $BIG_ISP is going to go to ARIN with justification for 
another /12 or so and they're going to get a few hundred /20s instead 
because that's all that's left.  Lather, rinse, repeat, and watch the v4 DFZ 
implode.  This will happen _before_ RIR exhaustion hits.

Hopefully, the $BIG_ISP folks of the world see this coming and are starting 
to tell CPE vendors that they will not buy/resell anything that doesn't do 
v6 after some fixed date.  The abject lack of v6 support in ISP-supplied CPE 
devices shows that if they are, that date is not yet imminent.

It's great we all have v6-capable hosts and core routers now, but that isn't 
enough; it's the CPE boxes (firewalls, DSL modems, etc.) that're going to 
eat us all alive in 3-4 years if things don't change Real Soon Now(tm). 
Kudos to Apple for being the first vendor to wake up; let's hope the others 
follow their lead in time to make a difference.


Stephen Sprunk      "Those people who think they know everything
CCIE #3723         are a great annoyance to those of us who do."
K5SSS                                             --Isaac Asimov 

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