As this recent article explains, it's the 11th hours for IPv4 address. If you haven't taken this threat seriously yet, maybe it's time.
The Handbook of IPv4 to IPv6 Transition: Methodologies for Institutional and Corporate Networks by John J. Amoss and Daniel Minoli
- Addresses the migration and macro-level scalability requirements
- Discusses IPv6 network constructs, AutoConfiguration techniques, and the suite of IPv6 and related protocols
- Describes IPv6 enterprise/institutional network migration scenarios and coexistence issues
- Examines scenarios and techniques for introducing IPv6 into carrier networks
- Explores application aspects of IPv6 transition, issues related to mobile environments, and security in IPv6 networks