Scenario: You're seeing lots of AAAA records being registered on your DNS servers. Since these records are registrations for IPv6 addresses, you're wondering why this is happening.
Suggestion: IPv6 addresses will only be registered in DNS if the computers have public IPv4 addresses assigned. This triggers the computers to activate 6to4 and these 6to4 addresses will then be registered in DNS. If the computers don't have public IPv4 addresses, no IPv6 addresses will be registered for them in DNS.
Mitch Tulloch is a seven-time recipient of the Microsoft Most Valuable Professional (MVP) award and widely recognized expert on Windows administration, deployment and virtualization. For more tips by Mitch you can follow him on Twitter or friend him on Facebook.