The Number Resource Organization (NRO) reports that the Internet has passed a critical stage, with remaining IPv4 addresses having fallen to just 9% (400 Million spare); IPv4 addresses are now expected to be completely depleted before the end of 2011. The news may get repeated each year but it is no less important and could result in serious problems for UK broadband ISPs that fail to adapt.

IPv4 addresses are assigned to your computer each time you go online (e.g. 123.23.56.98). It is a unique online identifier made up of four number groups and allows you to communicate with other computers around the world; not unlike a phone number for voice calls. Sadly you can only have so many IPv4 addresses and as a result IPv6 was designed.


Presently IPv4, used since 1984, provides roughly 4.5 billion addresses, of which only about 400 million remain free and available for new connections. By contrast IPv6 is plentiful and more secure by design. They are 128bits long, written in hexadecimal and separated by colons; for example:

2ffe:1800:3525:3:200:f8ff:fe21:67cf

Failing to adopt IPv6 in time could make it more difficult for broadband providers to add new customers and it may force others to share a single IPv4 address with several users, which could cause all sorts of legal and performance problems (e.g. imagine if one of those sharing your IP did something illegal).

The good news is that more ISPs are taking the problem seriously, though some still appear intent upon waiting until the last possible moment. Part of the reason for that is a perceived lack of demand and the costs involved with adapting an entire platform to work within an IPv6 world. Never the less it must happen.


It's difficult to predict exactly when IPv4 addresses will run out, though Unallocated IANA Address Pool Exhaustion is expected to hit around September 2011 and RIR will follow in August 2012. Suffice to say, as any network engineer will know, that doesn't leave much time left to get the job done.