This page contains some ideas for future improvements.
DNS Query Processing
- NSD takes many shortcuts like no additionals/authority if encounters CNAME loop, no additionals for referral.
- Why is synth DNAME->CNAME TTL 0? RFC6672 3.1 states: " A CNAME RR with Time to Live (TTL) equal to the corresponding DNAME RR is synthesized and included in the answer section when the DNAME is employed as a substitution instruction."
- query to ANY for CNAME traverses that CNAME, other servers don't do that (no RFC to back this up)