In message <D1AC4482BED7C04DAC43491E9A9DBEC3901E1628@BK-EXCHMBX01.blacknight.local>, at 02:10:47 on Sat, 25 Jan 2014, Michele Neylon - Blacknight <michele@blacknight.com> writes
I'm a bit confused by your assertions with respect to authoritative DNS.
Can you please provide examples of domains where the situation you described could exist?
Eg: "target domain name. In fact, for the sake of redundancy, a domain name may have many
authoritative servers, spread around the world and also operated by different companies."
{You know all this, so there's clearly some kind of terminology issue} Each domain is supposed to have two Name Servers (maybe we could also discuss whether that's a better, or more familiar, term to use in the text). There's no reason why they have to be adjacent either physically or on the same network (ie same AS). Best practice is supposed to be that they should be separated, although many commercial hosting companies appear not to. An over-complicated alternative example is the domain ripe.net, which has six such servers, only one of which is on ripe-ncc's network; the others are at nic.fr, apnic.net, isc.org and arin.net. http://mydnscheck.com/?domain=ripe.net In the diagram on page 6 of the document (and onwards), it would assist the reader a great deal if the 'example' website in question was not something associated with IANA, because currently it gives the very strong impression that IANA is hosting everyone's authoritative servers. I would suggest finding a suitable candidate, that isn't confusingly associated with any of the major I* organisations, with perhaps three diverse name servers. While not recommending it as the example for this paper, I note that intgovforum.org appears to have one hosting provider, with name servers on networks in Virginia, Georgia and Arizona. -- Roland Perry