DNS Behavior

[Stephane Bortzmeyer]

On Mon, Oct 15, 2007 at 02:33:14PM -0300,
 Pablo L. Arturi <parturi at bairesweb.com> wrote 
 a message of 117 lines which said:

> ;; Received 164 bytes from 192.52.178.30#53(K.GTLD-SERVERS.NET) in 206 ms < this is a root server

No, it is not.  K.GTLD-SERVERS.NET is not a root server. You can get
the list of root name servers with "dig NS ." (".", the dot, being the
root).

> Why for google.com.ar (or any other .com.xx domain) the answer
> doesn't comes from "athea.ar" (country specific root server) for
> example?

I do not see what could be a "country specific root server".

Otherwise, the difference between the ".com" name servers and the
".ar" name servers comes simply from the fact that the ".com" name
servers (wrongly) send the answer in the Answer section, while the
".ar" name servers, like most of the sensible name servers put it in
the Authority section, since they are not authoritative for the
data. I would say "blame Verisign".

% dig @K.GTLD-SERVERS.NET NS google.com

; <<>> DiG 9.3.4 <<>> @K.GTLD-SERVERS.NET NS google.com
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 35961
;; flags: qr rd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 4

;; QUESTION SECTION:
;google.com.                    IN      NS

;; ANSWER SECTION:
google.com.             172800  IN      NS      ns1.google.com.
google.com.             172800  IN      NS      ns2.google.com.
google.com.             172800  IN      NS      ns3.google.com.
google.com.             172800  IN      NS      ns4.google.com.

;; ADDITIONAL SECTION:
ns1.google.com.         172800  IN      A       216.239.32.10
ns2.google.com.         172800  IN      A       216.239.34.10
ns3.google.com.         172800  IN      A       216.239.36.10
ns4.google.com.         172800  IN      A       216.239.38.10

;; Query time: 133 msec
;; SERVER: 192.52.178.30#53(192.52.178.30)
;; WHEN: Mon Oct 15 22:53:57 2007
;; MSG SIZE  rcvd: 164

% dig @athea.ar NS google.com.ar    

; <<>> DiG 9.3.4 <<>> @athea.ar NS google.com.ar
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1567
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 0

;; QUESTION SECTION:
;google.com.ar.                 IN      NS

;; AUTHORITY SECTION:
google.com.ar.          14400   IN      NS      ns4.google.com.
google.com.ar.          14400   IN      NS      ns1.google.com.
google.com.ar.          14400   IN      NS      ns2.google.com.
google.com.ar.          14400   IN      NS      ns3.google.com.

;; Query time: 203 msec
;; SERVER: 200.16.98.2#53(200.16.98.2)
;; WHEN: Mon Oct 15 22:56:25 2007
;; MSG SIZE  rcvd: 113