[Pdns-users] pdns-recursor 3.7.4 on Redhat Linux always returns SERVFAIL for AAAA lookups

[Kenneth Marshall]

Hi PDNS users,

I am investigating a caching problem and the cause is that
the 3.7.4 recursor returns a SERVFAIL error for a AAAA lookup.
The AAAA record does not exist, but an A record does. According
to my reading:

https://www.ietf.org/rfc/rfc4074.txt

to have DNS cache applications realize that, there
should be a NOERROR response with an empty value for the content.
Is there anyway to get the 3.7.4 recursor to do that? I get the
error:

pdns_recursor[3935]: DNS parser error (a.b.c./AAAA from 127.0.0.1): a.b.c., Parsing record content: missing field at the end of record content ''

from the following lua script:

function preresolve ( remoteip, domain, qtype )
  ret={}
  if qtype == pdns.AAAA and domain == "a.b.c." then
    pdnslog ("fixing AAAA query " .. domain)
    ret[1]={qtype=pdns.AAAA, content=""}
    return 0, ret
  end
  return -1, ret
end

Is there anyway to do this in this version of the recursor?
Thank you in advance for any ideas.

Regards,
Ken