I did a lot of Perl and DNS hacking while working as a DNS administrator at a multinational company, and I did extensive Perl-DNS hacking. Amongst other things, I did a fully recursive DNSchecker that could check the entire internal tree, and give a report on lame delegations and stuff (and point out those pesky, non-standard Novell DNS servers. Ugh). I used the Net::DNS module to do a lot of work, and it was really helpful, check it out. It will help you do queries and take care of the responses correctly.