On Thu, 25 Aug 2011 20:45:04 +0200 Patrik Fältström <patrik at frobbit.se> wrote: > Specifically, I want to force queries over TCP. And then for example force queries over UDP with specific size of payload and other fun stuff (no fallback to TCP). Why exactly? Probably of no help but OpenBSD has a resolv.conf option to only use TCP. Maybe you could hack OpenBSD to conditionally do what you want or hack a DNS perl module.