[ppml] trade in your IPv4 block for an IPv6?

[Tony Hain]

Paul Vixie wrote:
> what if someone could get PI IPv6 space by agreeing to return PI IPv4
> space?
> 
> not the same day, mind you.  within two years, perhaps.  or five years.
> an
> exchange rate would have to be established, like "if you return a V4 /16,
> we
> will give you a V6 /48" or even "we'll give you a V6 /(49-N) for the N V4
> /16's you return".  the goal would be to shrink or keep stable the size of
> the routing table in dual stacked routers, while getting V4 space back
> that
> we can use for address lifetime extension later when V4 space gets short.
> 
> (i'm trying to think of some early adopter advantages that would have
> beneficial side effects.)

Encouraging early would be to set a decaying timer on the value of N. Tie
both the request date and the actual return date into the equation.
Something like 49-N with N=16 to start, and a decay of N at 2 per year.
Always round down to the even number (ie: /30 to start) then if the
organization returns the IPv4 space within the year they get the odd half
that had been rounded out. 

Tony