serve-expired-ttl

[Stephane Bortzmeyer]

On Thu, Jul 11, 2019 at 05:09:30PM +0200,
 Wouter Wijngaards via Unbound-users <unbound-users at nlnetlabs.nl> wrote 
 a message of 74 lines which said:

> Yes that is what it does.  Unbound also attempts to refresh and
> fetch the new correct value for the record, every time it is asked.
> That should bring the record back to the correct value.  Once it is
> available to be fetched.

I'm wondering about the mapping between Unbound and the future RFC 
draft-ietf-dnsop-serve-stale. If I read correctly the draft, the
resolver can send expired (stale) data only if the authoritative name
servers are not reachable. If so, serve-expired does not have the
proper behaviour. Is

serve-expired-ttl-reset: yes
serve-expired-ttl: 86400

more compliant with the future RFC? (I'm not sure it is possible to be
100% compliant with Unbound.)