> i took the words "at or below" to mean "in-bailiwick". caches that are > not organized as tree-like data structures still have to be able to find > the closest encloser, which means they do know ancestor/descendent > relationships, even if the data structure itself is otherwise flatishly > hashlike.
The most straightforward way to implement this is to say "FOO.BAR.COM"'s closest encloser is BAR.COM, and then look BAR.COM up in the cache. Which is fine when you _need_ to do that. It's not fine to do it on every query even when it otherwise would not have been necessary (which would be the vast majority of cases). But to implement this algorithm you need to start at the room, so first look at ".", then at "COM", then at "BAR.COM". That's three hash lookups if there's a cached NXDOMAIN, and four if there isn't. Blech. _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
