[dns-operations] Program/library/framework for testing robustness of servers

[Stephane Bortzmeyer]

I maintain an experimental authoritative DNS server and I would like
to test its robustness. dnsperf and flamethrower are great to test its
performance, zonemaster and dnsviz are perfect to test its correctness
in face of legal input but I would like to see how it reacts to
*illegal*, malformed input. (An example of such input is
<https://lists.dns-oarc.net/pipermail/dns-operations/2022-May/021657.html>.)

Since most DNS libraries are made to prevent the programmer for
issuing illegal DNS requests, it is not obvious to write such a test.

Are you aware of libraries / programs / frameworks to exercice, in a
hard way, the robustness of a server?