OT: Authoritative Server returning RR's with decrementing TTL's?

[Doug Barton]

Almost certainly not running BIND. Almost certainly is running a 
"creative" load balancing solution.

hth,

Doug


On 07/31/2014 12:56 PM, Ray Van Dolson wrote:
> Not BIND-related specifically... (though the server below could be
> running BIND I suppose).
>
> This seems weird.  Why is this authoritative server returning *some*
> answers with decrementing TTL's?
>
> $ dig @ns1.dtra.mil dtra.mil NS
>
> ; <<>> DiG 9.7.4-P1-RedHat-9.7.4-2.P1.fc14 <<>> @ns1.dtra.mil dtra.mil NS
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34658
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;dtra.mil.                      IN      NS
>
> ;; ANSWER SECTION:
> dtra.mil.               2002    IN      NS      ns1.dtra.mil.
> dtra.mil.               3359    IN      NS      ns2.dtra.mil.
>
> ;; Query time: 92 msec
> ;; SERVER: 214.27.180.254#53(214.27.180.254)
> ;; WHEN: Thu Jul 31 12:47:33 2014
> ;; MSG SIZE  rcvd: 62
>
> $ dig @ns1.dtra.mil dtra.mil NS
>
> ; <<>> DiG 9.7.4-P1-RedHat-9.7.4-2.P1.fc14 <<>> @ns1.dtra.mil dtra.mil NS
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22108
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;dtra.mil.                      IN      NS
>
> ;; ANSWER SECTION:
> dtra.mil.               1999    IN      NS      ns1.dtra.mil.
> dtra.mil.               3359    IN      NS      ns2.dtra.mil.
>
> ;; Query time: 90 msec
> ;; SERVER: 214.27.180.254#53(214.27.180.254)
> ;; WHEN: Thu Jul 31 12:47:35 2014
> ;; MSG SIZE  rcvd: 62
>
> Server behaves the same way even if I do the queries without recursion
> desired...
>
> Odd.
>
> Ray