dnscache and Amazon AWS
Background and summary
I run a split-horizon DNS system on djbdns at the moment. All systems at home hit dnscache on my central server for all resolution needs. djbdns being what it is, things run smoothly and efficiently and I've really all but forgotten about the setup until I ran into some trouble: initial attempts to hit netflix.com stall for minutes on end and access to the Movember American site has been flaky at best.
On initial inspection, it seems that this is linked to a resolution problem within dnscache: queries for (specifically) movies.netflix.com and us.movember.com end up with a
drop <N> input/output error
message in the dnscache logs. The thing these two sites have in common is that they're hosted at Amazon AWS... and it seems there is something about the DNS setup there that doesn't jive with dnscache.
The setup
For reference, here are the specifics of my setup at home:
