Gary Buhrmaster gary.buhrmaster at
Fri Nov 29 18:43:50 UTC 2013

On Thu, Nov 28, 2013 at 9:07 PM, Leo Vegoda <leo.vegoda at> wrote:
> Is a /60 what is considered generous these days?

I do not think so.  I think that is more minimal than generous.

> I thought a /48 was
> considered normal and a /56 was considered a bit tight. What prefix
> lengths are residential access providers handing out by default these
> days?

A /60 appears (by reports from AT&T and Comcast customers)
seems to be the current behavior for some residential access
providers.  I am sure one can find counter examples.

And while I can rationalize the thinking (I suspect few
home users currently use more than 16 internal networks),
with solutions that will eventually depend on further prefix
sub-delegation downstream (aka HIPNet), /60 feels a bit tight.
I would certainly feel more comfortable seeing the providers
start offering at least a /56, if not a /48, if requested by the

It is conceivable that the residential providers intend to offer
more than a /60 at additional costs (as they offer more than
one IPv4 address today), or to offer more than a /60 only to
those that request it (to minimize some perceived "waste"
of IPv6 numbers).  I would expect that "Business" customers
will almost certainly see different offerings (/48s?).  It is also
conceivable that the residential providers have not (yet)
thought it all through.


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