A brief history of IPv4 address space exhaustion

Unfortunately my perception is that IPv6 deployment is stalled (due to inaction by ISPs). In my company we have recently dismantled some of our IPv6 infrastructure because it became apparent that ubiquitous v6 connectivity was not coming any time soon (e.g. we have locations served by Charter&#x2F;Spectrum, and they have no IPv6 and no plan to deploy it). We&#x27;ve instead deployed a private IPv4 overlay network between our sites and assets using GRE tunnels.<p>Also somewhat exasperating that the &quot;running out of IPv4 addresses&quot; saga has played out across almost my entire career. I remember attending the CIDR meetings at the IETF in around 1992, for example. So one of the first technical problems I encountered in my career remains unsolved nearly 30 years later.

I now receive a block of IPv6 from Comcast. I allow the router to assign them to devices on the network, but I admit that I am somewhat worried that my local PC is no longer isolated from the Internet by a private IP.

I find DJB&#x27;s take on this interesting: <a href="https:&#x2F;&#x2F;cr.yp.to&#x2F;djbdns&#x2F;ipv6mess.html" rel="nofollow">https:&#x2F;&#x2F;cr.yp.to&#x2F;djbdns&#x2F;ipv6mess.html</a><p>EDIT: Dan has many excellent points, but I&#x27;d like to quote my favorite:<p><i>The IPv6 designers made a fundamental conceptual mistake: they designed the IPv6 address space as an alternative to the IPv4 address space, rather than an extension to the IPv4 address space.</i><p>Indeed, what were they thinking!<p>It&#x27;s certainly an undeniable fact that IPv6 adoption has been a disaster, taking much longer than hoped for. Frankly, I expect to see IPv4 coexist with IPv6 for the next hundred years - not ideal.

When I was at UCLA, I learned this new architecture called NDN <a href="https:&#x2F;&#x2F;named-data.net&#x2F;" rel="nofollow">https:&#x2F;&#x2F;named-data.net&#x2F;</a>. It does not rely on addressable device or host. It give addresses to content. Not sure how industry think of this new idea. I watched several talks about NDN. They all have great stories and believe it&#x27;s the future.

Corrections: CIDR stands for Class<i>less</i> Inter Domain Routing (because it superseded the Class A&#x2F;Class B&#x2F;Class C arrangement, which allowed only three particular allocation block sizes).

I know the author is Spanish; I&#x27;d like to point out Orange Spain has been deploying IPv6 addresses to end customers these last weeks using the Dual Stack lite transition system.<p>All the big ISPs have been testing IPv6 for years now and I&#x27;m sure it&#x27;s just a matter of flipping a switch. Now that a new contender is in town (a 4th ISP) and they&#x27;re having huge problems because they have no IP addresses left to assign to their customers, I suppose the rest of ISPs will stall even more their transition to IPv6 so they can try and &quot;suffocate&quot; the new ISP.<p>Just my two cents...

I&#x27;ve only worked at one company that had full IPv6 support. Even on my current 1GbE fibre setup with a small startup, they still don&#x27;t have IPv6 rolled out to residents yet. :(<p>I feel like one big hurdle is IPv6 usability. You can write down and easily remember IPv4 addresses. IPv6 netmasks can get really confusing. They make sense if you expand out every block, but in reality, IPv6 requires a lot of tooling to chop up and work with address spaces in an intuitive way.

<a href="http:&#x2F;&#x2F;www.internetsociety.org&#x2F;deploy360&#x2F;blog&#x2F;2017&#x2F;05&#x2F;google-buys-a-12-ipv4-address-block&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.internetsociety.org&#x2F;deploy360&#x2F;blog&#x2F;2017&#x2F;05&#x2F;google...</a>

If you enjoyed this, this is a great resource current state of prefix utilization in the global routing tables:<p><a href="http:&#x2F;&#x2F;www.cidr-report.org&#x2F;as2.0&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.cidr-report.org&#x2F;as2.0&#x2F;</a>

IPv4 is like any commodity. Now that it&#x27;s not easily to get from ARIN, a market has sprung up around buying and selling it.<p>It&#x27;s still relatively easy to get IPv4 blocks for a buck or two per IP through auction houses.

Would have been awfully nice to have a reserved bit in hindsight. 7 bit ASCII was an amazing accident. (Maybe it wasn&#x27;t, time to brush up on my history...)

IANA sold the blocks. There are still a lot of unused IPv4 addresses. IANA sold the blocks.<p>PS IPv6 sucks.

We only use 32 bits of each 48 bit ipv4 address. The problem isn&#x27;t exhaustion, it&#x27;s using DNS to do service location rather than IP.