[arin-ppml] *Spam?* Re: Discussion Petition of ARIN-prop-125 Efficient Utilization of IPv4 Requires Dual-Stack

Jason Schiller schiller at uu.net
Wed Dec 29 15:46:24 EST 2010

On Tue, 28 Dec 2010, Kevin Kargel wrote:

|I must concur with Owen on all points.  I have an IPv6 allocation, and I 
|am fighting hard to get native IPv6 routing from my upstream(s).  The 
|only reason I can see to support 125 would be a completely selfish one in 
|that I have predominantly met the requirements and that it would make the 
|remaining pool more accessible to me because of the number of entities 
|that would be disqualified from accessing it because they have not worked 
|toward meeting the IPv6 requirements.
|I am not willing to put my selfish concerns ahead of the community.  If 
|it is desired to force one protocol by requiring another protocol as a 
|pre-requisite, then there are more appropriate standards bodies to 
|accomplish that than a registrar.  (IETF?  IEEE?)  I suspect such an 
|attempt within the standards bodies would be rejected out of hand as it 
|should be here.  
|Can you imagine any of the standards organizations accepting a proposal 
|that says interfaces without an IPv6 address must not have an IPv4 

So over a decade ago IETF decided to make IPv4 and IPv6 incompatible on 
the wire.  This was by design.  This leaves an obvious transition problem, 
how to allow IPv4-only systems to talk to IPv6-only systems.

The IETF supported solution was dual-stack, with the expectation that all 
IPv4-only systems that need to talk to the entire Internet will go 
dual-stack.  Thus as the Internet continues to grow, and that growth gets 
fulfilled by creating IPv6-only networks and hosts, that these 
pre-existing systems will already be dual-stacked and there will not be a 
transition / translation issue.

Unfortunately this has not occurred.  I suspect this it primarily due to 
economic factors.  Since there is real cost in deploying IPv6, and no new 
revenue or services, I suspect organizations are deferring the costs for 
as long as possible.  

Hopefully people have already done all the analysis, have guessed 
correctly when the industry depletion date is, have correctly estimated 
the cost and time required for such a deployment, have started their work 
in time, and will be ready to embrace IPv6 in a real way when the first 
organizations begin to be forced to fulfill their new growth through 
IPv6-only.  This date is shortly after the frist RIR depletion, possibly 6 

If however this does not happen, then the gap between the IPv4 Internet 
and IPv6 Internet may remain large (as it is now).  As such many of the 
new IPv6-only networks will be unable to reach large portions of the 
Internet.  That gap may take a substantial amount of time to close.  If 
that is the case then we will all be forced to use transition technologies 
like NAT 64 & DNS64 or NAT 46 and DNS46, or lots of layers of CGN NAT4444.  
As the Comcast trial suggests, these technologies have substantial 
performance degradation that customers do complain about.  

If a small handful of large providers make a determination that they can 
defer their IPv6 deployment for a few years because they can continue to 
get IPv4 addresses, then this would certainly draw out the transition 
period and increase pain for everyone. This would also likely force their 
competition to seriously consider getting additional IPv4 addresses so 
that they are not at a competitive disadvantage (e.g. their customers can 
only get to the 5% of content on the Internet that is dual stacked).  If 
the majority of a content provider's customer base is IPv4, then much of 
the incentive to move to dual-stack is removed.  New content, or growth of 
existing sites, would require IPv4 addresses as the majority of traffic 
would be IPv4.

I suggest it is good for the community at large to move to providing 
connectivity to both protocols (IPv4 and IPv6) prior to organizations 
being forced to deploy IPv6-only hosts and networks in order to minimize 
the transition pain.  This means all Internet facing  content needs to 
be reachable over both protocols, and any product or service for which the 
need for IP addresses continues to grow needs to go IPv6.  Furthermore 
future content may be deployed as IPv6-only, and as such all pre-existing 
IPv4 networks need to plan to support IPv6 as that content emerges.  

Ensureing that all growth going forward supports both protocols sends a 
clear signal that the Internet is ready to embrace IPv6 and is prepaired 
to transition future growth to IPv6-only when necessary.  This is exactly 
the demand the content providers and application developers need to 
justify their investments in IPv6. It also gives people the time to work 
out any issues they have with IPv6, and removes the penelty of being among 
the first providers to be forced into IPv6-only world.

Some have suggested that the pricing of the IPv4 market will solve this 
problem.  The problem with that approach is those that have calculated 
that they plan to purchase IPv4 addresses will still have a long lag time 
to implement IPv6 once they realize that IPv4 addresses are priced above 
the cost of IPv6 deployment, or entirely out of thier reach.  The end 
result is still a long and painful transition / translation period for 
all, and the possibility of slowing or stalling IPv6 adoption.  


More information about the ARIN-PPML mailing list