Maintained by: NLnet Labs

[Unbound-users] Parent child disagreement problem

Mike Emigh
Thu May 13 06:17:11 CEST 2010


Hi guys,

We ran across a new problem in what appears to be parent-child
disagreement on version 1.4.4.  The resolution appears to work as
expected when digging for A records in the domain, but if you first
dig for the NS (starting with an empty cache), then subsequent A
record lookups fail.

If you dig safesvc.gov.cn NS, it returns an invalid response:

;; ANSWER SECTION:
safesvc.gov.cn.         3600    IN      NS      netdns.

Then trying to resolve an A record from this domain results in a SERVFAIL:

;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 1462
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.safesvc.gov.cn.            IN      A


The A query appears to work as expected if the you never issue the
'dig safesvc.gov.cn NS' command.

Mike