Number of additional records in queries

[Joe Abley]

On 18 Oct 2020, at 16:04, Tony Finch via Unbound-users <unbound-users at lists.nlnetlabs.nl> wrote:

> Brown, Chris via Unbound-users <unbound-users at lists.nlnetlabs.nl> wrote:
> 
>> So my question is...am I missing something in some RFC that would break
>> the rules to send non-opt records along with OPT records in the
>> ADDITIONAL section of queries?  Or is this just a sanity call Unbound
>> made for...well...some sanity and maybe safety.  Missing something else?
> 
> I think the only other records you can legitimately put in a query are
> TSIG, TKEY, and SIG(0).

This feels like one of those situations where even if there's no prohibition on additional, arbitrary records being included in the additional section, there's also no known reason for a query to include them and hence no reliable behaviour that could be expected of a system processing that query and generating a response.

I don't think 1035 has any clear advice on the contents of the answer, authority or additional sections in messages with QR=0. That document is far from the final word on these matters, of course.


Joe