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Re: Definitive Guide to IPv6 adoption


From: Owen DeLong <owen () delong com>
Date: Tue, 19 Oct 2010 02:06:16 -0700


On Oct 18, 2010, at 2:39 PM, Doug Barton wrote:

On Mon, 18 Oct 2010, Owen DeLong wrote:

I think it's generally a bad idea. /48 is the design architecture for IPv6. It allows for significant innovation in 
the SOHO arena that we haven't accounted for in some of our current thinking.

Q:    Why are /48s everywhere a good idea?
A:    Because it's the design!

Q:    Why are /48s everywhere in the design?
A?    Because it's a good idea!

Which of course ignores the second half of my comment...

This kind of crap is one of the reasons people get frustrated with IPv6 zealotry. If people are actually interested 
in deploying IPv6 then by all means, STOP BITCHING AT THEM ABOUT HOW THEY DO IT. Problems like the wrong allocation 
to end users are fixable, especially given that the vast majority of end user assignments are dynamic in the first 
place.

Unless those problems become endemic and start reducing the lowest common denominator to which vendors feel they must 
implement.

There are advantages to being able to use 16 bits to build various forms of hierarchical topology on a dynamic basis 
within a SOHO environment. If we reduce that to 8 bits, we will block innovations that are currently underway in this 
space.

The model I've been advocating is for ISPs (who have enough space) to start off reserving a /48 per customer and then 
assigning the first /56 from it. If after real operational experience it turns out /48 is the right answer, you're 
all set. If /56 turns out to be sufficient, when you use up all of the first /56s you can start on the first /56 in 
the second /49, etc.

Uh, yeah, why not just get your /32 (or whatever larger prefix you started with) expanded or get an additional prefix 
to put the additional customers into? Then, you're still set and you haven't had to block or reduce capabilities your 
customers should be able to accept.

Owen



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