The vast majority of networks today, including the Internet, are based on the Internet Protocol, version 4 (IPv4) protocol. Developed over 25 years ago, IPv4 is showing its age. Its 32-bit addressing cannot accommodate the explosive growth worldwide of network-connected devices, particularly in Asia and China. Moreover, IPv4 was not designed with security in mind and its security solutions have not kept pace with the expanding requirements of IP-based networks. These deficiencies are addressed by IPv6.