Wolf wolf (was: Re: OT: Fwd: The Root has got an A record)

[Mark Andrews]

> In article <die91d$2gss$1 at sf1.isc.org>, Ketil Froyn <ketil at froyn.name> 
> wrote:
> 
> > Great reason not to use the public-root.net servers, isn't it?
> > 
> > _THE_ root-servers don't have an A-record. _A_ root-server does, but 
> > it's an unofficial one. You should have made it clearer that this is on 
> > an alternate root.
> 
> Even if it were the official root servers, what's the problem?  Under 
> what circumstances would an application try to get the address of the 
> root, and why would it depend on getting an empty answer?

	"." is often used as a place holder domain name.

	"MX 0 ." made a great "I don't want email" marker.

	Adding a A/AAAA records to "." means that applications that
	don't check for "." will suddenly start trying to contact
	the address rather than failing with address unknown.

	Looks like we need to add a explict check for "." to
	getaddrinfo(), gethostbyname() etc.  Applications that bypass
	the library and talk directly to the DNS need to add similar
	checks.

	Note: "." is not a legal hostname (RFC 952 / RFC 1123).

	Similarly 0.0.0.0 and :: are good place markers in the DNS
	for I don't currently have a address but I do exist.

	Mark

> -- 
> Barry Margolin, barmar at alum.mit.edu
> Arlington, MA
> *** PLEASE post questions in newsgroups, not directly to me ***
> 
> 
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org