Please don't try to engineer other people's networks because they are not going to listen to you. It is a fact that 240/4 addresses work fine except for one line of code in IOS, MS-Windows, Linux, BSD, that explicitly disallows packets with this address. People have already provided patches for Linux and BSD so that 240/4 addresses work normally. Cisco would fix IOS if the IETF would unreserve these addresses, and likely MS would follow suit, especially after Cisco makes their changes.
Now, please explain the magic method you're going to use to cause that "one line of code" to be removed from more than a billion devices that are currently able to use the Internet. Remember that a lot of these devices are deployed in spots such as little gateway NAT devices owned by John Doe at 123 Anydrive, and so when he is unable to get to some website because some brilliant hosting service has chosen to place a bunch of servers on 241.2.3.0/24, his reaction is most likely going to be "so and so sucks" and move onto a competitor's web site. Further, when one of your magic clients with the "updated" version of Windows XP that supports "IPv4-240+" and the misfortune to actually *BE* on one of those decides to contact pretty much any existing website on a VPS that's on "auto pilot", and there's a ton of those, dontchaknow, we are talking a problem significantly worse than "failed to update bogon filters". Not only does the hosting company have to fix their bogon filters, but they also have to fix the TCP stack on every server under their control, which is going to be extremely labor intensive. Do we want to start discussing all the other places that knowledge of network classes is built into software, and the subtle ways in which things may break, even if they appear to "work" for some crappy definition of "work"? Please don't try to re-engineer the entire IPv4 Internet because you'd like a small additional allocation of IP space that isn't currently usable. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.