"DK" may not be hierarchical, but "DK." is. If you try to resolve "DK" on it's own, many (most? all?) DNS clients will attach the search string/domain name of the local system in order to make it a FQDN. The same happens when you try and resolve a non-existent domain. Such as alskdiufwfeiuwdr3948dx.com, in wireshark I see the initial request followed by alskdiufwfeiuwdr3948dx.com.gateway.2wire.net. However if I qualify it with the trailing dot, it stops after the first lookup. DK. is a valid FQDN and should be considered hierarchical due to the dot being the root and anything before that is a branch off of the root. see RFC1034
-Jeremy On Sun, Jun 19, 2011 at 7:08 PM, Mark Andrews <ma...@isc.org> wrote: > > In message <g339j59ywz....@nsa.vix.com>, Paul Vixie writes: > > Adam Atkinson <gh...@mistral.co.uk> writes: > > > > > It was a very long time ago, but I seem to recall being shown > http://dk, > > > the home page of Denmark, some time in the mid 90s. > > > > > > Must I be recalling incorrectly? > > > > no you need not must be. it would work as long as no dk.this or dk.that > > would be found first in a search list containing 'this' and 'that', where > > the default search list is normally the parent domain name of your own > > hostname (so for me on six.vix.com the search list would be vix.com and > > so as long as dk.vix.com did not exist then http://dk/ would reach > "dk.") > > -- > > Paul Vixie > > KI6YSY > > DK should NOT be doing this. DK is *not* a hierarchical host name > and the address record should not exist, RFC 897. The Internet > stopped using simple host names in the early '80s. In addition to > that it is a security issue similar to that described in RFC 1535. > > Mark > -- > Mark Andrews, ISC > 1 Seymour St., Dundas Valley, NSW 2117, Australia > PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org > >
