Unable to understand why a different A record response being sent by bind

[Nico CARTRON]

Hi Harshith,
On 20 June 2016 at 15:05:58, Harshith Mulky (harshith.mulky at outlook.com) wrote:

I am Running bind (bind-9.9.5P1-2.2.2.x86_64) on Open Suse 13.2



I have the following Records in my Zone file



$ORIGIN test1.com.
$TTL 600
@  IN      SOA     atlanta.test1.com. admin.test1.com.  (
                                      2003022720 ; Serial
                                      56800      ; Refresh
                                      14400      ; Retry
                                      3600000    ; Expire
                                      2h )    ; Minimum

              IN      NS      atlanta.test1.com.


atlanta.test1.com.  IN A    10.54.48.68
;A Records

denver1.test1.com.  IN A    10.54.80.150
denver1.test10.com.  IN A    10.54.80.17
denver2.test1.com.  IN A    10.54.80.150
  IN A    10.54.80.35
test1.com.  IN A   10.54.80.150


When I am doing a dig for the record denver2.test1.com. for A

I am receiving this Response:

dig denver2.test1.com. A

; <<>> DiG 9.9.5-rpz2+rl.14038.05-P1 <<>> denver2.test1.com. A
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42085
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;denver2.test1.com.         IN      A

;; ANSWER SECTION:
denver2.test1.com.  600     IN      A       10.54.80.150
denver2.test1.com.  600     IN      A       10.54.80.35

;; AUTHORITY SECTION:
test1.com.         600     IN      NS      atlanta.test1.com.

;; ADDITIONAL SECTION:
atlanta.test1.com. 600   IN      A       10.54.48.68

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Jun 20 18:22:29 IST 2016
;; MSG SIZE  rcvd: 122


Question:

1. I am not able to understand why this answer is being Received
denver2.test1.com.  600     IN      A       10.54.80.35
as I have not configured any owner-name for the record type
It’s not an “owner”, it’s a RR (Resource Record) ;)
In your zone file you have:

denver2.test1.com.  IN A    10.54.80.150
  IN A    10.54.80.35

So BIND interprets the 2nd line as a 2nd value for denver2.test1.com., which makes perfect sense.



2. If there is no owner-name specified in the DNS Records, what owner-name does the record actually pick?
See above: it’ll pick the previous line where you have a RR defined.



Cheers,

-- 

Nico

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/bind-users/attachments/20160620/20518349/attachment.html>