Is it safe to use 240.0.0.0/4

Thu Jun 18 01:39:29 UTC 2015

>> Given how slowly IPv6 is deploying, this choice may prove to have been
>> shortsighted.
> 
> I doubt it. As you said, there is A LOT of crap out there that would have to be updated. Pulling a number out of the air, I'd guess *most* in-use devices would NEVER see such an update. Even from companies that do still exist. (Sadly, those are also devices that aren't going to see IPv6, either.) 

Most stuff out there do only care about that its subnet mask OR's up correctly with its ip and gw. Poof, there did 99.9 per cent of all devices get excluded. Most stuff that do use and/or misuse this freightening block of darkest cyberspace are either high end network equipment (who drop) or some end users/mcast sender which are behind NAT anyway.

I believe it's a great idea. Let's at least try it out, like an alpha-test. We choose a temporary /8 (easy to remember) and divide it into /16s or less, depending on how many interested candidates we are able to raise. After being approved by IANA we begin advertising our new prefixes for a finite amount of time. If the world ends, or is about to, we stop.

I believe we would bump into minor caveats but ISP's are beginning to NAT their end customers due to the lack of free ips and I wouldn't want to live in a world where that was the norm. This madness has to stop and v6 won't salvate us for yet another total sonar eclipse or three.

Let us at least try it out - if it goes well we have bought us some time. If not, revert.
Thank you for listening.

br /Mr Bjork