[arin-ppml] ARIN-prop-127: Shared Transition Space for IPv4 Address Extension

Jack Bates jbates at brightok.net
Fri Jan 21 09:17:54 EST 2011

On 1/21/2011 3:31 AM, Mark Smith wrote:
> The proposal doesn't mention another source of unique IPv4 addresses
> that could be used for this purpose - the ISPs' existing assignments.
> It'll be functionally equivalent to a NAT444 /10, and will preserve
> more of the remaining public address space for purposes where truly
> globally unique IPv4 addresses are necessary. It would mean ISPs would
> have to start sharing their existing addresses sooner rather than
> later, but that is better for the customers - the longer that ISPs avoid
> introducing address sharing, the larger the shock to customers when the
> ISP can't avoid it any longer and has force customers to share
> addresses all at once. A gradual address sharing roll out would be far
> better than an abrupt one, for both the ISP and it's customers.

This was our original idea. I disagree with the gradual roll out, 
though. From a support view point, it's better to hard cut the network 
after the trial network issues and performance have been worked out. The 
idea, and hope in holding off is to minimize the shock to customers by 
allowing others to support IPv6 (including those home routers). As IPv6 
becomes more prevalent, we can quick shift v4 into CGN to cover the left 


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