[dns-operations] NXDOMAIN for some types and not others (Was: Too Open (Was: OpenDNS makes your Internet work better

[Florian Weimer]

* Stephane Bortzmeyer:

> ~ % dig AAAA www.nic.rf 
>
> ; <<>> DiG 9.2.4 <<>> AAAA www.nic.rf
> ;; global options:  printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 25198

Good catch.  This results in a DoS attack vector if you put another
caching resolver between your clients and the OpenDNS servers. 8-/