Adding four more bits to the Left of the Source Address and setting those bits to 1111 (0xF) can help to start the migration to "Regions" and more IPv4 Addresses - Using and Re-Using legacy spectrumhttp://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.txt 16 /8s for "Future use" - it looks like the "Future" has arrived 240/8 Future use 1981-09 RESERVED [15] 241/8 Future use 1981-09 RESERVED [15] 242/8 Future use ... 253/8 Future use 1981-09 RESERVED [15] 254/8 Future use 1981-09 RESERVED [15] 255/8 Future use 1981-09 RESERVED [15] http://tools.ietf.org/html/draft-gundavelli-v6ops-community-wifi-svcs-014.13. Overlapping IPv4 Address Support Wi-Fi Service Provider may segment the network into regions. Two regions may use overlap IPv4 address space. This is particularly important when the Internet is transitioning to IPv6. The Wi-Fi SP may not have enough unique public IPv4 addresses to globally address large number of Wi-Fi device.