BIND 8.2.2 can return referral for recursive query

[Ian Jackson]

I've discovered that BIND 8 (and perhaps other versions of BIND) can
sometimes return a referral (ie, a reply with no answers, no error,
and some NS records and no SOA record in the authority section) even
if recursion is desired and available.

See the dig output and log message below.

Is this a sensible behaviour on the part of BIND ?  What should a
stub resolver do when it gets this response ?  What I do at the moment
is print a warning message and return an error code for `server gave
invalid response'.

(This is all in the context of adns, the GPL'd stub resolver I wrote
as an alternative to libresolv and gethostbyname.  For more details,
see http://www.chiark.greenend.org.uk/~ian/adns/.)

May 22 11:02:42 chiark named[221]: bad referral
(1.196.121.209.in-addr.arpa !< *.121.209.in-addr.arpa)

May 22 11:02:42 chiark named[221]: bad referral
(1.196.121.209.in-addr.arpa !< *.121.209.in-addr.arpa)

-chiark:~> dig -vt ptr 1.196.121.209.in-addr.arpa.

; <<>> DiG 8.2 <<>> -vt ptr 1.196.121.209.in-addr.arpa.
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 2
;; QUERY SECTION:
;;      1.196.121.209.in-addr.arpa, type = PTR, class = IN

;; AUTHORITY SECTION:
*.121.209.in-addr.arpa.  1D IN NS  pri1.dns.psi.ca.
*.121.209.in-addr.arpa.  1D IN NS  pri2.dns.psi.ca.

;; ADDITIONAL SECTION:
pri1.dns.psi.ca.        10h36m22s IN A  154.11.136.2
pri2.dns.psi.ca.        20h39m51s IN A  154.11.145.2

;; Total query time: 414 msec
;; FROM: chiark to SERVER: default -- 127.0.0.1
;; WHEN: Mon May 22 11:02:42 2000
;; MSG SIZE  sent: 44  rcvd: 146

-chiark:~>
(This comes up nearly immediately.)
-- 
Ian Jackson                  personal email: <ijackson at chiark.greenend.org.uk>
These opinions are my own.        http://www.chiark.greenend.org.uk/~ijackson/
PGP2 public key id 0x23f5addb, fingerprint 5906F687 BD03ACAD 0D8E602E FCF37657