On Wed, Dec 29, 2010 at 9:26 PM, David F. Skoll <[email protected]> wrote:
> I'm not sure I agree with that. The smallest unit of IPv6 address > space allocated by a provider (even to an end-user) is likely to be a > /64, so I don't see why whitelists can't list /64's too. Essentially, > I disagree with the phrase "which by their nature list individual IP > addresses". It's not certain that ISPs will always allocate /64. Some may allocate /56 or something entirely different, and shared hosting providers may allocate smaller ranges to their customers (why not an individual IP to each customer?). Enterprise users may be happy with announcing specific /128s for their one to four mailservers. And so on: Regardless of allocation policy, a protocol must support varying netmask lengths. Specifying "/64 only" or "/128 only" is not going to work. For dnswl.org, I see situations where we will use an ISP-provided-to-an-enduser range (/64 or whatever), and others where we will have smaller ranges (down to /128s, and possibly something in between /64 and /128). -- Matthias
