rdns, past and future

[Ken Dreyer]

On Tue, May 26, 2020 at 3:56 PM Greg Hudson <ghudson at mit.edu> wrote:
> On 5/26/20 5:09 PM, Ken Dreyer wrote:
> > In public cloud environments or Kubernetes environments, PTR records
> > are difficult or impossible for administrators to set. We increasingly
> > have to tell users to set "rdns = fallback" or "rdns = false".
>
> Note that dns_canonicalize_hostname and rdns are separate settings.
> dns_canonicalize_hostname supports "fallback", but rdns only supports
> true or false (and only takes effect when DNS canonicalization happens).

My bad, you're right. I meant dns_canonicalize_hostname=fallback.

I've found some public cloud providers with some very weird PTR
records for IP addresses that they hand out. These records are worse
than NXDOMAIN, and I was confused to see these in my logs.

- Ken