[Pdns-users] CNAME NXDOMAIN problem

[Francois Claire]

> Appears that you receive nxdomain from nameserver, see at the end of trace.
>
> Aki
>
>
Indeed the g2.ebay.com. DNS server (66.211.167.40) answers 
thumbs.g.ebay.com. with an NXDomain:
14:13:38.023503 IP W.X.Y.Z.4994 > 66.211.167.40.53: 26515 [1au] A? 
thumbs.g.ebay.com. (54)
14:13:38.196462 IP 66.211.167.40.53 > W.X.Y.Z.4994: 26515 NXDomain*- 
0/1/1 (96)

But when using dig, the g2.ebay.com. DNS server answers a CNAME record:

$ dig @66.211.167.40 thumbs.g.ebay.com

; <<>> DiG 9.8.4-P2 <<>> @66.211.167.40 thumbs.g.ebay.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58678
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;thumbs.g.ebay.com.        IN    A

;; ANSWER SECTION:
thumbs.g.ebay.com.    60    IN    CNAME c.ebay.georedirector.akadns.net.

;; Query time: 177 msec
;; SERVER: 66.211.167.40#53(66.211.167.40)
;; WHEN: Thu Nov 21 14:41:08 2013
;; MSG SIZE  rcvd: 80


So why is the powerDNS recursor receiving an NXDomain ? Is its query 
malformed ?



To reproduce the problem is easy: just use the "dig thumbs.g.ebay.com" 
command on your pdns_recursor server.