Glue Records for TLDs
James Raftery
james-bind-users at domainregistry.ie
Mon Jul 31 10:03:35 UTC 2000
On Sun, Jul 30, 2000 at 03:25:41PM +0700, Stefan Probst wrote:
> So, in real-life situation you
> would never get an authoritative answer from them, but always be forwarded
> to another server. I think this is what they meant, when I read something
> somewhere, that you don't get an authoritative answer from a root server.
I suppose in essence, yes. The 'normal' queries sent to the root servers
would elicit a non-authoritative response, as they would be about
domains delegated from the root, such as COM, NET, SE, FI etc, rather
than about the root itself.
> In other words: How can I know, that the non-authoritative
> answer for "hydra.helsinki.fi." which I get from a root server is really
> from a glue record in the root zone and not from an A record in the fi.
In theory, you can't. A cache entry is a cache entry and you can't tell
from the response you get from a nameserver how records got into the
cache. In practice though, the root servers have a specific purpose.
They announce the root zone. The guidelines for operating a root server
say that it should not suport recursion or any other function which
would allow anything other than locally supplied information (i.e. the
contents of a zone file) to be be announced. From that you can make an
educated guess that records are from the root zone.
As a aside, the root zone is available from
ftp://rs.internic.net/domain/root.zone.gz
if you want to see what it actually looks like.
Regards,
james
--
James Raftery (JBR54) - Programmer Hostmaster - IE TLD Hostmaster
IE Domain Registry - www.domainregistry.ie - (+353 1) 706 2375
"Managing 4000 customer domains with BIND has been a lot like
herding cats." - Mike Batchelor, on dns at list.cr.yp.to.
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