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

Joe Maimon jmaimon at chl.com
Sun Oct 10 04:29:48 EDT 2010

Owen DeLong wrote:
> On Oct 9, 2010, at 10:46 PM, Christopher Morrow wrote:
>> On Sun, Oct 10, 2010 at 12:00 AM, Owen DeLong<owen at delong.com>  wrote:
>>> We will cause harm by being stingy with address space beyond these points.
>> you've mentioned (at least 2x in the last 3 days) that /48's for
>> consumer end sites permit heirarchical dhcpv6-PD, can you explain how
>> the you see this working? and more importantly why you can't do PD on
>> ... just about any other boundary? Why can't I do PD of a /64 or /60
>> inside an already PD'd /56 to my home gateway? (or is this just
>> inconvenient?)
> For better or worse, /64 as the end subnet size is pretty well codified
> and required for SLAAC. So, PD of /64 is a non-starter.

Its only as codified as we all allow it to be by continuing to give 
SLAAC veto power over the rightmost 64 bits.

Its early days yet. In comparable v4 history, it was the leftmost bits 
that were well codified.

There are alternatives to slaac, and apipa has already shown that 16 
bits is sufficient in todays world.

Toss in privacy concerns and slaac is starting to look stodgy.

Automatic numbering and subnetting schemes in v6 are going to have to be 
a bit more bit flexible if they are to withstand the test of time.

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.


More information about the ARIN-PPML mailing list