[arin-ppml] IPv6 Transition Policy (aka Soft Landing)

[Joe Maimon]

Owen DeLong wrote:
>    
> That ship really has sailed. SLAAC is deployed, people are using it. Breaking SLAAC would
> be a bad thing.
>
>    
Fixing slaac would be a good thing. Its absurd to allow something barely 
a decade old control the next several. If it is still a good idea, keep 
it, if it is a better idea to modify it, do it.
>    
> I'm not sure what you mean by apipa, but, no, 16 bits isn't sufficient for a stateless scheme.
>    

It works now. It can work better with more but it does not necessarily 
require 64.

> It doesn't get much more flexible than SLAAC except for the requirement for EUI-64 based
> end system identifiers.
>    
Does this requirement bear out in anything other than slaac?
>    
>> In other words, pdv6 would have to ripple up the chain and cause subnet shortening on the fly all the way up in order to be fully robust.
>>
>>      
> Now you're throwing random technologies in a blender and postulating what comes out.
>
> DHCPv6 PD does actually allow for shortening on the fly as you describe, but, most implementations
> don't. However, the problem is that if the shortened result is the CPE->ISP router requesting a
> prefix larger than the ISP can or will give, it doesn't matter how much dynamic shortening occurred
> or not.
>
> Owen
>
>
>    
If shortening smaller than 64 was available, it would be much more 
robust, regardless of what was available >64 from the ISP. It would work 
at least as well as apipa for another 48 bits, which is quite deep 
hierarchically.

Joe