Google Public DNS Problems?

Blair Trosper blair.trosper at gmail.com
Wed May 1 17:07:44 UTC 2013


Goes all the way up to the A root server before failing spectacularly.

Europa:~ blair$ dig +cd @8.8.8.8 google.com A

; <<>> DiG 9.8.3-P1 <<>> +cd @8.8.8.8 google.com A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 47332
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

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

;; AUTHORITY SECTION:
. 467 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2013050100 1800
900 604800 86400

;; Query time: 46 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed May  1 10:05:46 2013
;; MSG SIZE  rcvd: 104


On Wed, May 1, 2013 at 9:58 AM, Casey Deccio <casey at deccio.net> wrote:

> On Wed, May 1, 2013 at 9:38 AM, Blair Trosper <blair.trosper at gmail.com>
> wrote:
> > That's all well and good, but I certainly wouldn't expect "nslookup
> > gmail.com" or for "nslookup google.com" to return SERVFAIL
> >
>
> If you set the CD (checking disabled) in the request, a response that
> would normally be SERVFAIL due to DNSSEC validation failure will
> return with the non-authenticated answer.  With dig the flag to add is
> "+cd".  I don't know if there's an equivalent for nslookup.  For
> example:
>
> dig +cd @8.8.8.8 google.com
>
> Casey
>


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