The question of an unused range of IPV4 addresses with a prefix 240/4 from time to time becomes the topic for discussions in the community of developers and network engineers. This range, consisting of 268 million addresses, was reserved for “for” for “for” future targeted modes”, as indicated in RFC 1112. However, despite the gradual exhaust of free IPV4 addresses, this reserve It remains non-allocated, which causes bewilderment among experts: why is a quarter of a billion IPV4 addresses still not used when the global network is in dire need of additional resources?
In 2008, two projects of proposals for using the 240/4 range were submitted. One of them, the project Wilson-class-e, suggested using this The range in private networks, which could help in the transition of large organizations to IPV6 in conditions of dual-stack architecture (IPV4/IPV6). This solution would allow large networks to avoid conflicts with existing private ranges (1918bis), such as 10/8, which are already actively used, and would simplify the interaction of network equipment with the translation of traffic through NAT.
Another project, Fuller-240Space, offered to make the range available for general use, since by 2010-2012 years the complete exhaustion of free IPV4 addresses was predicted. However, as experts noted, the deployment of support for addresses from the range of 240/4 into millions of devices around the world would require tremendous efforts, which would distract attention from the main task – an accelerated transition to IPV6.
As a result of the discussion about the fate of the range of 240/4, flared up in 2008-2009,