[arin-ppml] IPv4 is depleted today - unrealistic statements about IPv6 inevitability

Stephen Sprunk stephen at sprunk.org
Wed Sep 3 00:42:48 EDT 2008

Howard, W. Lee wrote:
>> -----Original Message-----
>> From: arin-ppml-bounces at arin.net 
>> [mailto:arin-ppml-bounces at arin.net] On Behalf Of Robin Whittle
>> Sent: Monday, September 01, 2008 9:42 PM
>> To: ppml at arin.net
>> Subject: Re: [arin-ppml] IPv4 is depleted today - unrealistic 
>> statements about IPv6 inevitability
>>                  The only routers which will be affected
>>                  significantly by the growing number of DFZ routes
>>                  will be those of transit providers and large ISPs
>>                  where the routers have the highest number of
>>                  neighbours.  I believe the operators of those
>>                  routers will always find it better to upgrade or
>>                  replace those routers, or to limit the number of
>>                  neighbours they connect to, rather than drop some
>>                  DFZ routes and therefore provide a second-rate
>>                  service.
> Those operators tell me there are no routers available or planned
> that can handle the projected volume of routes and updates.  One
> of the engineers for a router company you'll recognize told us about
> a year ago that Moore's Law is approaching its limits regarding
> routing scalability.
> http://www.arin.net/meetings/minutes/ARIN_XX/ppm1_transcript.html#anchor
> _7
> Look for "MR. LI".

With all due respect to Tony (and I mean that sincerely), it seems like 
every year I've been in the tech biz, someone is shouting that the sky 
is falling and we've finally hit the wall on Moore's Law, yet a year 
later some other person has come up with a magical solution that saves 
us all and puts that particular crisis off for another year or two.  I 
hate to rely on that trend continuing, but given the track record so 
far, I find it hard to believe otherwise, despite Tony's statistics.  I 
remember when folks were telling us x86 CPUs couldn't run faster than 
100MHz, and they had lots of great statistics too, yet now the same 
folks are talking about how the 4GHz barrier is insurmountable...

> The problem is not that transit providers and large ISPs don't want
> to upgrade.  They do like to test their equipment before they put
> it into production, but mostly, they like that equipment to exist
> before they design their network around it.
> Buy Jason Schiller a drink and ask him about "routing to the left."
>>                  The most likely response to the IPv4 routing
>>                  scaling problem and the related shortage of
>>                  IPv4 space (caused largely by the current BGP
>>                  only system being unable to slice the space
>>                  up finely without bloating the DFZ routing table)
>>                  is a Core-Edge Separation solution such as LISP,
>>                  APT, Ivip or TRRP.  (Six/One Router is also a
>>                  Core Edge Separation solution, but it only works
>>                  for IPv6.)  This could be used as the basis for a
>>                  new kind of IPv4 global mobility.
> Many people have advocated here for a split between routing 
> identifier and host identifier.  Most were discussing IPv6.  I
> don't think this forum can help much in that debate, look over 
> there --------------------->  IETF

ITYM the RRG of the IRTF.  The output of that work will eventually make 
it to the IETF for standardization.

>> But what sort of configuration work, software upgraded, 
>> complexities, flakiness, support calls etc. would be required 
>> for ordinary end-users to run their home networks dual stack 
>> successfully?
> Any OS released after 2006?

That ignores all the apps and CPE devices (mostly DSL/cable "modems", 
which have an integrated NAT/FW function) that don't understand IPv6.  
Even if upgrades were available, which in most cases are not, you still 
have to get all the users to install them...

Or, we could just get NAT-PT working.  At least one vendor is already 
shipping it.


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