Today the news was announced that IANA, the organisation ultimately responsible for allocating IPv4 addresses to the Internet community, has just allocated a further 4 blocks of /8 in one day.  Two of these went to ARIN, the Regional Internet Registry for the North America, one went to AfriNIC, the RIR for the continent of Africa, and one to RIPE NCC, the RIR for Europe.

This means that we now have 7 blocks of /8 left out of a total of 256.  At the beginning yesterday we had 11.  This basically cuts the total free IPv4 space remaining from 4.3% to 2.7%, a decrease of almost half.  Current estimates as of yesterday were predicting that the IPv4 address space would run out at the beginning of March, but with addresses being used so quickly, that might well be December or January.

So what happens now?  Well, as of now, there are 7 /8s left.  If a further two blocks of /8 are allocated, this leaves 5 remaining.  IANA policy is believed to be that when only 5 blocks of /8 are remaining, they will be distributed equally to each of the five RIRs – that is, ARIN, RIPE NCC, LACNIC, AfriNIC and APNIC.  If (as is likely) APNIC require one or more blocks (most probably because of China’s insatiable appetite for new addresses), this means we could be down to 5 /8s very quickly.  And at that point, the last five will be distributed evenly, and we will have run out at IANA, possibly before Christmas.

This begs the question – why is almost no-one is ready for it?  Out of the “sticking plaster” options, Carrier Grade NAT is certainly one solution, (that is, effectively NATing and/or PATing the NATs) but this only works so well until we either run out of addresses *and* TCP/UDP ports, but also means that we will be double, triple or even quadruple NATing our hosts.  This scuppers any chance of PAT (Port Address Translation) working unless all the NATs do the PAT, which is unlikely to be workable, especially when one or more of the NATs are being run by unprepared-for-IPv6 ISPs, and this means that no-one will successfully be able to run servers behind NAT.

So please, ISPs, please stop thinking about rolling out Carrier Grade NAT which will cost ££££££s and start rolling out IPv6 which will also cost ££££££s.  It will cost you less in the long run.  (But I doubt they’re going to listen to me, so if you don’t mind, I’ll just get my metaphorical IPv6-enabled deckchair and sit in it eating my metaphorical IPv6-enabled popcorn whilst watching the chaos ensue.  It really isn’t going to be pretty.)

At some point, the procrastinating ISPs (which currently seems to be all of them) will need to wake up.  Perhaps this will be when people can’t access Google, Facebook, YouTube, iPlayer, <insert popular new service here only available on v6>.  But I can pretty much guarantee the IPv6 roll out will be done in a rush and badly.  If only people had started thinking about this 5 years ago (like the ISP I use did…)