[Pdns-users] SERVFAIL on backend failure - is this possible?

Vytenis A vytenis.adm at gmail.com
Wed Feb 26 00:00:49 UTC 2020

Hi Bert,

Thanks for a prompt reply.

This is currently on my local test VM, it's waay past midnight, I can
put it on resolvable domain tomorrow if this isn't helpful. Not sure
how to show you this exactly :)

I'm using latest pDNS, using official repo:

pdns-4.2.1-1pdns.el7.x86_64, CentOS 7.7.1908

Two backends:

# /etc/pdns/pdns.conf:


Static bind backend contains one zone, which contains SOA and one 'IN
NS' record only.

http endpoint is serving TXT records exclusively, and all is well if
it's reachable: queries get resolved, nonexistent TXT records get

But if http endpoint is invalidated (as in example above ^) - I get
NXDOMAIN. If I remove bind stuff out of pdns.conf - I get REFUSED,
which is somewhat the same as SERVFAIL afaik.

bind backend is used to keep SOA out of "remote" backend, not 100%
sure it's the best way. We could implement entire zone in http backend
as a last resort.

Thanks again!

On Wed, Feb 26, 2020 at 12:51 AM bert hubert <bert.hubert at powerdns.com> wrote:
> On Wed, Feb 26, 2020 at 12:35:21AM +0200, Vytenis A via Pdns-users wrote:
> > While trying to implement authoritative DNS server using "remote"
> > backend, I've stumbled into an issue when HTTP backend is unreachable
> > - PowerDNS is returning NXDOMAIN.
> Can you reproduce this for us so we can check? It is not supposed to ever
> happen. Please also let us know which version of PowerDNS you are using.
> > What I would like to achieve is return SERVFAIL in case my HTTP
> > endpoint is unavailable. Is this possible? Maybe Lua fallback backend
> > could assist here?
> This is what should be happening.
>         Bert


More information about the Pdns-users mailing list