Skip Navigation

The end of IPv4 is nigh - addresses near exhaustion
Wednesday 01 December 2010 11:33:10 by John Hunt

The end of IPv4 is nigh - well nearly. We are approaching the depletion of the current unallocated IPv4 address space with only seven /8 IP blocks remaining in the IANA (Internet Assigned Numbers Authority) pool. IP addresses are a limited resource with only around 4 billion available to be used. A new protocol, IPv6, has been developed which operators are slowly starting to support which will eventually replace IPv4, but it is likely IPv4 will still be used for many years to come.

IANA control the allocation of these IP address blocks to the regional IP address registries and once there are only five remaining blocks, they will be handed out, one each, to each of the Regional Internet Registries (RIR's) who handle allocations in their local area, (such as ARIN in North America and RIPE NCC in Europe). The current predicted date for IP's running out is March 5th 2011, but some suspect this could be sooner. When this date comes, the RIR's are expected to last for around 8 months before depletion of their available address space occurs, with the Asia/Pacific region (managed by APNIC) expected to run out first.

When this happens, we may start to see a shift change on the Internet with IPv6 starting to become more widely used and available as IPv4 becomes a scarce resource. There is the possibility of a two-tiered Internet where some who are stuck in an IPv4 world are not able to access sites which are hosted only on IPv6. Currently few broadband providers in the UK offer IPv6 connectivity, even though AAISP has offered it since 2002. Broadband router manufacturers are also lagging behind in support for IPv6 although this is improving slowly.

Here at thinkbroadband, we have supported IPv6 for over two years. To see if you are connecting to us via IPv6 or to find out more information, see our IPv6 guide. Our advanced ISP search also lets you find broadband providers who offer IPv6, although we only have three listed at the moment: AAISP, Exa Networks and IDNet - others are known to be in trials at the moment. If you are a UK broadband provider and currently support native IPv6, we'd love to hear from you.


Posted by GMAN99 over 6 years ago
:) We've been told the end was nigh for years

I heard that a lot of 4 addresses had been given up and made available again?

Also I can't see why ipv4 customers couldn't access v6 sites, there have been ipv4 to ipv6 tunnels for years.
Posted by john (Favicon staff member) over 6 years ago
Some have been given up, but not enough to make a big difference. You can do tunnels, but there could end up being some areas that get left behind without full access..
Posted by mhisani over 6 years ago
"A new protocol IPv6 has been developed which operators are slowly starting to support which will eventually replace IPv6"

I think you mean replace IPv4.
-Mhisani Fox
Posted by john (Favicon staff member) over 6 years ago
Thanks for that. Have fixed the typo!
Posted by rolinux over 6 years ago
I reckon in few years (2-5) the ISPs will start charging for IPV4 also sold as a static IP address and the rest of the people will go behind NAT for IPv4 traffic and receive enough IPv6 addresses.
But will take 2 years for the Top 100 sites to be available for IPv6 and many more years before most of the traffic moves there.
It's not only the frontend server to be IPv6 compatible but all the logs need to be processed correctly so this will be code change on most of the online software.
Posted by KarlAustin over 6 years ago
Router manufacturers are NOT lagging behind at all - they all have support for IPv6 if their ISP customers request it. Until they do, they won't put the code in to the firmware - I know this from speaking to the person in charge of router design for ISPs at one of the largest manufacturers. Basically the ISPs don't want to pay for it to be included in the models they ship to customers and as they are by far the largest customers, they basically say what goes in.
Posted by john (Favicon staff member) over 6 years ago
KarlAustin: IMO it should come as a standard feature as its just an alternative to the basic IPv4 connectivity.

It's not like they won't have to do it eventually, so manufacturers should bite the bullet and just stuff it in to everything. I guess by making things not-compatible though there is more chance of additional revenue from sales of newer models.
Posted by chrysalis over 6 years ago
karl thats sounds ridicolous given that isp's usually have custom firmware anyway. so eg. BE who supply a st585 with bebox firmware, why would that have an impact on what goes in retail firmware?
Posted by otester over 6 years ago
Manufacturers aren't going to go the extra mile if they don't have to, why should they?
Posted by GMAN99 over 6 years ago
Firmware for end users isn't really the issue, at the end of the day its a firmware update I don't think for a second the hardware in current routers can't run ip6, when its needed I expect vendors will release the firmware. People should be more concerned on the ISP's running 6 within their core networks that's where the complications are.
Posted by chrysalis over 6 years ago
gman99 that is backwards thinking, most tech products have features that are not needed but are a luxury. ipv6 takeup will obviously be hindered if there is a lack of equipment to utilise it. on ipv4, there is still many ip's allocated but unused.
Posted by GMAN99 over 6 years ago
Its not backward thinking. I'm saying its not a worry. Its a firmware fix, I'm positive the equipment out there right now is more than capable of running ipv6, home networks only have a single route back to the Internet its not a massive overhead neither is local addressing. Its more of a problem in the core of the network. I expect when its offered by more ISP's then router manufacturers will start supplying updates
Posted by jtevans over 6 years ago
I have been tracking the routing growth at

for some years. The associated address exhaustion prediction counter at

is of interest.
You must be logged in to post comments. Click here to login.