amoffat/focus — pull request #6 by fawek (2012-05-15 15:34:38+00:00)
Title: Keep TTL unchanged for hosts that are not blacklisted

I'm not sure how much of a difference this would have in practice - AFAIR, some browsers do have their own local DNS caches with their own arbitrary TTLs (for Chrome, it's one minute) as they do not have access to those returned along with the DNS records. But it seems like the right thing to do, especially for slower DNS servers.

In general though, it'd probably be better to have the server return only invalid records for blacklisted domains and unknown host responses for others and just let the OS try with the other servers and handle the TTLs properly (right now, only the first name server is tried for non-blacklisted hosts).