dig +short doesn't work when querying root DNS server?

Question

I've found that if I query a UK root DNS server directly (e.g 195.66.240.130) it provides a result in 2-5ms vs querying a regular DNS server which takes 15-40ms.

However, for some reason the +short option doesn't work when querying 195.66.240.130

Works: dig @8.8.8.8 example.co.uk NS +short

Doesn't work: dig @195.66.240.130 example.co.uk NS +short

Does anyone know why?

If I remove +short then all relevant info is shown but I'm trying to get the output cleanly.

Answer 1

The +short option is to print the ANSWER section from the response which may be empty (in the case of referral answers) as you can see from the example below:

[vitalie@silver ~]$ dig @195.66.240.130 bbc.co.uk NS

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_5.3 <<>> @195.66.240.130 bbc.co.uk NS
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63811
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 4

;; QUESTION SECTION:
;bbc.co.uk.                     IN      NS

;; AUTHORITY SECTION:
bbc.co.uk.              172800  IN      NS      ns1.thdo.bbc.co.uk.
bbc.co.uk.              172800  IN      NS      ns1.rbsov.bbc.co.uk.
bbc.co.uk.              172800  IN      NS      ns1.thls.bbc.co.uk.
bbc.co.uk.              172800  IN      NS      ns1.bbc.co.uk.

;; ADDITIONAL SECTION:
ns1.bbc.co.uk.          172800  IN      A       132.185.132.21
ns1.thdo.bbc.co.uk.     172800  IN      A       212.58.224.21
ns1.thls.bbc.co.uk.     172800  IN      A       132.185.240.21
ns1.rbsov.bbc.co.uk.    172800  IN      A       212.58.227.48

;; Query time: 57 msec
;; SERVER: 195.66.240.130#53(195.66.240.130)
;; WHEN: Wed Dec 22 15:12:29 2010
;; MSG SIZE  rcvd: 179