From a government network security consultant: The vendors recommend disabling IPv6 because they understand that it is hard enough to harden just IPv4. By disab

From a government network security consultant: The vendors recommend disabling IPv6 because they understand that it is hard enough to harden just IPv4. By disabling IPv6 on government networks, you minimize the number of places a security auditor can miss something thus hopefully improving overall security. IPv6 really does require a new set of skills to secure so it is better to be old, simple, and proven (or at least we know where most of the problems are), than new, advanced and unknown when you are talking about security.