Biggest mistake for IPv6: It's not backwards compatible, developers admit

[Thomas Jacob]

On Thu, 2009-03-26 at 15:51 +0000, Steve Wilcox wrote:
> Well, it was designed 15 years ago with the intention that it would be
> rolled out in less than aforementioned time period, without a sudden
> urgency brought on by slow adoption! So to be fair, the design
> probably could have been better but I guess they were still living in
> a time period when widescale protocol changes were do-able and taken
> seriously...
> 
> Steve

I am sure some people here have already read DJBs abrasive views on the
matter but if you compare the IPv4/IPv6 switch to the introduction
MX records in the 80s, as he does, it seems already at that
time some people were aware of workable methods for making
such protocol changes be adopted quickly.

http://cr.yp.to/djbdns/ipv6mess.html

The introduction of support for CIDR routes into the BGP protocol in 94
might be considered another example of prior art.

Sure those things are less fundamental then the layer 3 protocol.

On the other hand, this last statement might equally well be used in
support for the opposite thesis.

But being wise after the fact is always easy ;)

   Thomas