DNS and BIND discusses one of the Internet's fundamental building blocks: the distributed host information database that's responsible for translating names into addresses, routing mail to its proper destination, and many other services. As the authors write in the preface, if you're using the Internet, you're already using DNS -- even if you don't know it. The third edition covers BIND 4.9, on which most commercial products are currently based, and BIND 8, which implements many important new features and will be the basis for the next generation of commercial name servers. It also covers topics like DNS security (greatly improved with BIND 8.1), asynchronous notification of changes to a zone, dynamic updates, and programming with Perl's Net::DNS module. Whether you're an administrator involved with DNS on daily basis, or a user who wants to be more informed about the Internet and how it works, you'll find that this book is essential reading. Topics include: What DNS does, how it works, and when you need to use it How to find your own place in the Internet's name space Setting up name servers Using MX records to route mail Configuring hosts to use DNS name servers Subdividing domains (parenting) Securing your name server: restricting who can query your server, preventing unauthorized zone transfers, avoiding bogus name servers, etc. Mapping one name to several servers for load sharing Troubleshooting: using nslookup, reading debugging output, common problems DNS programming, using the resolver library and Perl's Net::DNS module