A hidden stock of good IPv4 addresses ?

[Ninho]

Folks, here's a question - not that I don't think that IPv6 (or at least, big IP addresses) are going to be necessary at a point, but, please bear with me :

IIRC in principle IPv4 prefixes 224.0.0.0/4 (otherwise said : 224.../8 to 239.../8) were reserved for multidiffusion, but in actual fact only (part of) 224.0.0.0/8 is ever used, right ?

Further, 240.0.0.0/4 are reserved (and unused), right again ?

Couldn't 225.0.0.0 to 254.255.255.255 be attributed for use as a large, fresh stock of unipoint IPv4 addresses, if we really wanted to prolong IPv4's life ?

[kriteknetworks]

Why the concern for prolonging ipv4? The idea is to promote adoption of ipv6.

[Ninho]

Why the concern for prolonging ipv4? The idea is to promote adoption of ipv6.

Look (once more) at what I wrote above, I didn't try to repeal adoption of IPv6 did I ?  ;=)

Nonetheless,thirty-some /8 worth of IPv4 addresses seem far from neglectable quantity, if they are indeed usable as such.

[jimb]

While it may be possible to prolong the life of IPv4 by reassigning experimental, unused (martians) and underutilized ranges of IPv4, it would only yield up a few more chunks of V4 address space, and delay the inevitable.  Also, certain ranges are regularly blocked in routers/firewalls, etc, and IPv4 stacks would also probably need to be reconfigured to treat some ranges as unicast, etc, etc.

So it could possibly be done, but it's obviously more desirable to just go to IPv6.

[snarked]

Why delay?  IPv6 works.  The amount of time this would give us is probably less than a decade.  Only if IPv6 weren't ready would this be a consideration.

Older devices may have behavior for those ranges hardcoded into firmware, and that would be a real pain to change.

By the same reasoning, we don't need to reserve ALL of the RFC 1918  and other ranges: 0/8 (except 0.0.0.0), 10/8, 127/8 (excluding 127.0.0.1), 165.254/16, 172.16/12, and 192.168/16, etc....  Simply declare 127/8 as "localnet", with 127.0.0.1 always being localhost (127.0.0.0 should be allocated to that also), and deploy the rest as accessible.

[jimb]

Exactly.  A lot of IPv4 devices would have to be revamped to allow the use or repurposing of various parts of the IPv4 space.  It'd probably be equal, if not more work than simply going to IPv6.

I just wish more ISPs would get on the ball about IPv6.  My current ISP (which I still have a year and half of contract with) has no plans to do IPv6.  At least Comcast is moving forward.

[ssorel]

*facepalm*