v6 subnet size for DSL & leased line customers

Christopher Morrow christopher.morrow at gmail.com
Sat Dec 22 15:03:28 UTC 2007

On Dec 22, 2007 1:45 AM, Mark Townsley <townsley at cisco.com> wrote:
> Joe Greco wrote:
> > I'd say skip the /64 and /48.  Don't do the /64, as future-proofing.  A
> > /48 is just something I cannot see need for, given the number of addresses
> > available as a /56, unless the "home user" is actually providing
> > connectivity to a bunch of his nearby friends and neighbors.
> >
> > Having fewer options is going to be easier for the ISP, I suspect.
> >
> Not just the ISP, but the home user, and the designers of the devices
> for the home. As you point out, device configuration in the home needs
> to be as simple as possible. It would be nice if designers of new
> networked home devices (particularly those that that would like to use
> media types which might not be readily bridged to other common media
> types) could have some reasonable assurance up front that they have the
> option of an IPv6 subnet in the home to use. This would then be one less
> thing to try and automatically discover, ask the user to configure
> information about, develop a workaround for, etc. Less options is a very
> good thing here, and rampant /64s could well paint the device
> manufacturers into a corner on what tools IPv6 gives them to take
> advantage of.

can you expound some on the last part of this? the 'rampant /64's..'
part? Since auto-conf pretty much requires the LAN to be /64 sized and
if you believe more than 1 subnet would be of use to the
end-user/residence then there are only a few options left, eh? It
seems that the ppp-o-e sorts of connections could pass out this
information and make the lives of equipment/user easier, what sort of
options were you envisioning? (or what were you hoping to avoid?)

I ask because I'm fairly certain the operator and standards-body folks
both would be curious about a vendor's (or vendor-ish-person's view)
view on this issue, I just don't think a rational answer is
forthcoming from the 'user' community on this quite yet :(


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