>IIRC, the short answer why it wasn't repurposed as additional unicast >addresses was that too much deployed gear has it hardcoded as >"reserved, future functionality unknown, do not use." Following an >instruction to repurpose 240/4 as unicast addresses, such gear would >not receive new firmware or obsolete out of use quickly enough to be >worth the effort.
More to the point, the amount of work required to fix all the existing equipment to handle 240/4 would not be a lot less than the work required to get it to handle IPv6, and it would only have pushed the IPv4 exhaustion out a few years. It was entirely reasonable to conclude that it would not have been a good use of anyone's time or money. Look at the bright side: you can use the money you didn't spend on 240/4 upgrades to buy slightly used IPv4 space on the grey market or CGN equipment. R's, John
