The coming of IPv6 represents the introduction of a new protocol stack, rich in features and, if the past is any guide, an interesting set of challenges for cyber security. IPv6 is already being used to bypass web proxies, to get around torrent rate limiting by ISPs, and it integrated into the Metasploit Framework. Most sites will be running IPv4 and IPv6 for the foreseeable future, increasing the complexity of network traffic and creating more opportunities for attackers. Current cyber security practices (e. g. ping all addresses to find active hosts) and tools will require rethinking and reengineering. The talk will cover both current recommendations for IPv6 configuration and open issues requiring further discussion and investigation.