Surprising successful resolution

Unbound
1

I believe this response should be a SERVFAIL instead:

; <<>> DiG 9.6.1-P2 <<>> www.fokus.gmd.de txt
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55433
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 3, ADDITIONAL: 2

;; QUESTION SECTION:
;www.fokus.gmd.de. IN A

;; AUTHORITY SECTION:
fokus.gmd.de. 7200 IN NS dns.gmd.de.
fokus.gmd.de. 7200 IN NS gaia.fokus.gmd.de.
fokus.gmd.de. 7200 IN NS helios.fokus.gmd.de.

;; ADDITIONAL SECTION:
gaia.fokus.gmd.de. 7200 IN A 193.174.154.10
helios.fokus.gmd.de. 7200 IN A 193.174.154.5

;; Query time: 1068 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Jan 19 20:15:08 2010
;; MSG SIZE rcvd: 124

dns.gmd.de (129.26.8.82) is lame (it returns a delegation to itself),
and the other servers don't respond at all.

It doesn't make a difference in practice, but I'm still surprised. :sunglasses:

2

Hi Florian,

This last packet is not deemed to be a lame-delegation-to-itself, but
instead a noerror-nodata answer. Obviously if the server has somehow
records for the zone NS that it can share, it has records for the zone.
It does not set the AA bit, yes. Unbound is treating it as if it is an
open recursor - hence the weird delegation that it gives (like a
delegation from cache). Therefore it is attempted as a last resort to
query that server. Hence the resolution of this query.

Best regards,
   Wouter