On Fri, Feb 22, 2013 at 01:39:21PM -0500, Jay Ashworth wrote:
but since the dot is a separator (I believe by definition), if it exists at the end, it has to be separating *something*.
Without getting into metaphysics, we can think of the dot in the presentation format as representing the separators in the wire format. In the wire format, of course, these separators are octets that indicate the size of the next label. And since the final label is null, the separator indicates a zero length in the wire format. Therefore, in the presentation format, the final separator is indicative of the (null) root label after. But if we want to skirt metaphysics, the problem here is the status of the presentation vs. wire format. If these are two perfectly co-equal forms of representation, then we have a funny problem, since in the global DNS the wire format is _never_ a relative lookup (the search path gets appended before lookup). If on the other hand the presentation format is merely one for human consumption, and the wire format is canonical, then there's just a representational problem. This of course doesn't actually help with the original question, which is how to refer to all these things unambiguously. I have no idea how to solve that: the different terms have an established use, and fixing ambiguities in established use is a problem far beyond the bounds of networking. A -- Andrew Sullivan Dyn, Inc. asullivan@dyn.com v: +1 603 663 0448