Reducing IPv4 Address Waste: IPv4 Unicast Extensions Project

 

Reducing IPv4 Address Waste: IPv4 Unicast Extensions Project

Seth Schoen

IPv4 address shortages have been exacerbated by the fact that a significant fraction of the IPv4 address space has never been available for numbering hosts. Decisions from the early 1980s reserved several hundred million addresses for "future use" and other purposes, and those addresses are now going to waste. While reversing this is complicated, it would be extremely useful in light of the acute demand for IPv4 address space. We don't know exactly how much compatibility we can achieve over time, but we think it would be better to start now in order to have more options later (much as it would have been a good idea to go ahead with unreserving 240/4 when it was proposed about 14 years ago; it would be nice to have a 14-year head start on using those addresses today). The IPv4 Unicast Extensions Project is proposing software and standards changes to allow the option to eventually bring reserved addresses into use. Some of our changes have been accepted in systems including Linux and FreeBSD, and we've proposed four Internet-Drafts at IETF, one of which received quite a bit attention on NOG mailing lists. This talk will present our work and ideas about reclaiming address space, and respond to some concerns raised by the community in response to our proposals.

Reducing IPv4 Address Waste: IPv4 Unicast Extensions Project (pdf)