Re: US DoD and IPv6

On Oct 10, 2010, at 7:02 PM, Dave CROCKER wrote:

> 
> 
> On 10/10/2010 2:51 PM, Steve Crocker wrote:
>> A compatible solution would have been better, but I don't think IPv4... --
>> were designed in a way that permitted a compatible extension.
> 
> 
> Oh?
> 
> Perhaps:
> 
>   1.  Adopt an IPv6 as Steve Deering originally designed it[1]:  A basic upgrade to the IPv4 header, with more address bits, an extensibility mechanisms for adding fields later, and removal of some bits that weren't needed.
> 
>   2.  Define the IPv6 address space as the IPv4 address space, with all zeroes for the higher bits.  (In other words, defer more interesting schemes until later.)
> 
>   3.  Design header translation devices to map between the two formats.
> 
>   4.  Start fielding these implementations.  (That could have started by 1994 or so.)
> 
> The "gateways" between v4 and v6 would initially be notably for having almost no work to do and of not losing any information.  In particular, barely qualifies as a "dual" stack.
> 
> With this approach, "incompatibility" between v4 and v6 would only occur when additional addresses, beyond v4's limitations, start to be assigned.
> 
> We must deal with the current reality and make it work, but historical considerations need to factor in the ambitions that dominated during the many years of design.
> 
> The community got ambitious in a fashion that smacked of the overreaching that is often called second system syndrome (although counting the Arpanet, this was really a third system...)

Dear Dave;

Not being directly involved at the time, I have always wondered this :

Was it second system syndrome, or was a slowness to realize that the time to drastically change the system increased from 
months to (effective) infinity somewhere between 1988 and 1994 ?

Regards
Marshall

> 
> d/
> 
> [1]  http://tools.ietf.org/html/draft-deering-sip-00
> -- 
> 
>  Dave Crocker
>  Brandenburg InternetWorking
>  bbiw.net
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