About TTL

Sumit Mehrotra sumit at cs.bu.edu
Fri Feb 9 09:09:34 UTC 2001


Hello BIND-users

I am running an authoritative NS for coptic.net domain. The NS is 128.197.14.80.When I dig at 128.197.14.80 for www.coptic.net I get a reply with TTL of 60 sec, which is what I have set up in the db files.

However, when I dig for www.coptic.net, the default NS (128.197.12.2) of a linux box that I work on, I get the TTL as greater that 60sec ( something to the order of 86400 sec).

I was wondering how this could happed, if 128.197.12.2 cached an answer from 128.197.14.80 for www.coptic.net, it should have cached the TTL as 60 sec? 
128.197.12.2 is using BIND 9.1.0
128.197.14.80 is using BIND 8.2.2 P7 if this is any help.

Attached are the db files and dig results 

Thanks
- Sumit
================================
db.coptic.net
-------------
$TTL    60
coptic.net.   IN     SOA     dhruv.coptic.net. hostmaster.dhruv.coptic.net. (
                                            2000012100
                                            10800
                                            3600
                                            604800
                                            3600
                                            )

                    IN      NS      dhruv.coptic.net.
                    IN      MX     10   mail.coptic.net.

coptic.net.             IN      A       128.197.10.20
mail.coptic.net.        IN      A       128.197.10.20
dhruv.coptic.net.       IN      A       128.197.14.80

www                 IN      CNAME   coptic.net.
------------------------

% dig @128.197.12.2 www.coptic.net

; <<>> DiG 9.1.0 <<>> @128.197.12.2 www.coptic.net
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6837
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3

;; QUESTION SECTION:
;www.coptic.net.                        IN      A

;; ANSWER SECTION:
www.coptic.net.         80886   IN      A       128.197.10.20

;; AUTHORITY SECTION:
coptic.NET.             167286  IN      NS      ATLNS01.WEBHOSTING.INTERLIANT.COM.
coptic.NET.             167286  IN      NS      ATLNS02.WEBHOSTING.INTERLIANT.COM.
coptic.NET.             167286  IN      NS      DHRUV.coptic.NET.

;; ADDITIONAL SECTION:
ATLNS01.WEBHOSTING.INTERLIANT.COM. 71988 IN A   209.196.32.34
ATLNS02.WEBHOSTING.INTERLIANT.COM. 71988 IN A   209.196.32.38
DHRUV.coptic.NET.       71988   IN      A       128.197.14.80

;; Query time: 3 msec
;; SERVER: 128.197.12.2#53(128.197.12.2)
;; WHEN: Fri Feb  9 04:04:48 2001
;; MSG SIZE  rcvd: 195


-------------------------

% dig @128.197.14.80 www.coptic.net

; <<>> DiG 9.1.0 <<>> @128.197.14.80 www.coptic.net
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54839
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;www.coptic.net.                        IN      A

;; ANSWER SECTION:
www.coptic.net.         60      IN      CNAME   coptic.net.
coptic.net.             60      IN      A       128.197.10.20

;; AUTHORITY SECTION:
coptic.net.             60      IN      NS      dhruv.coptic.net.

;; ADDITIONAL SECTION:
dhruv.coptic.net.       60      IN      A       128.197.14.80

;; Query time: 3 msec
;; SERVER: 128.197.14.80#53(128.197.14.80)
;; WHEN: Fri Feb  9 04:05:35 2001
;; MSG SIZE  rcvd: 108





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