How to fix a "THROWAWAY" response

[Havard Eidnes]

> To answer my own question,
>
> I went back to unbound V1.17.1 and I do not have the problem I
> described below.
>
> So I am at a loss to say why this is happening.
>
> The only difference to make the web site work with V1.18.0 is
> to turn off ipv6

In my opinion you didn't adequatly describe the relationship
between your unbound resolver and the (unnamed) web site.  Is
unbound performing resolver duties for the host running the web
site?  Or are they really unrelated?  Is unbound only serving the
web client host(s)?  Also, you were also very unspecific about
what with the web site is not working.  The devil is often
lurking in the details.  Is unbound unable to look up the address
info for the web site?  Or are your clients unable to connect to
the web site in question using IPv6?

You say that turning off "do-ipv6" works around the issue.  Does
the web site in question serve contents over IPv6?  Does it have
an AAAA record in the DNS (if "yes" to the former question it
should be a "yes" to the latter)?  Does the name servers for the
zone where the web site address is registered have AAAA records
registered?  Does your unbound host have IPv6 reachability issues
related to those name servers?

Of course, if you have broken or severely hampered IPv6
connectivity, trying to use IPv6 for either name resolution or
for actual content transfer is going to cause problems.  For
content transfer it's of course your web client's IPv6
connectivity which matters, and not (primarily) your unbound name
server.

It would probably bring you closer to figuring out what the
actual underlying problem is (or was) if you figured out the
answers to a few of the above questions.

Best regards,

- Håvard