v6 subnet size for DSL & leased line customers

Sat Dec 22 20:53:52 UTC 2007

On Dec 22, 2007 12:23 PM, Ross Vandegrift <ross at kallisti.us> wrote:
>
> On Fri, Dec 21, 2007 at 01:33:15PM -0500, Deepak Jain wrote:
> > For example... Within one's own network (or subnet if you will) we can
> > absorb all the concepts of V4 today and have lots of space available.
> > For example... for the DMZ of a business... Why not give them 6 bits
> > (/122?) are we anticipating topology differences UPSTREAM from the
> > customers that can take advantage of subnet differences between /64 and
> > /56 ?
>
> I am confused on this point as well.  IPv6 documents seem to assume
> that because auto-discovery on a LAN uses a /64, you always have to
> use a /64 global-scope subnet.  I don't see any technical issues that
> require this though.  ICMPv6 is capable of passing info on prefixes of
> any length -  prefix length is a plain old 8bit field.
>

Uhm, so sure the spec might be able to do something different than /64
but most equipment I've used only does auto-conf if the prefix is a
/64 :( Somewhere along the path to ipng we got reverted to classful
addressing again :(

-Chris