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Have you ever heard the term IPv4 Exhaustion? All IPv4 organizations are alarming everyone to move to IPv4, that there are limited amounts of IPv4 and that they should change now to IPv6 for the internet to continue to work. To what extent do you think that is indeed real?

Basics 101

IPv4 was one of the first protocols invented for the internet to work. As it stands on its name it stands for Internet Protocol Version 4. What happened to the other versions? Well the other versions were basically mistakes. They were not designed properly, they lacked functionality and stability. These versions were introduced between 1973-1977 [1]

Now an IP is an identifier for a computer, a network, an Apple Watch, an iPhone, you name it. All your devices in your house have an IP address be it a private ip or a public ip.

A private IP is a set of reserved IP addresses used for internal use. This means, they are only accessible inside a LAN or Local Area Network. This means, that in your house, you see your iPhone as , your Apple Watch as and your computer as and so on. This can be repeated in all houses, imagine how the world would be if all devices had a public IP address.

The equivalent of this would be like living on an apartment block. You all have the same main street address, but you have internal numbers such as apartment 101 within your address. This allows for a greater use of street numbers. Just imagine if apartments in Manhattan, New York, had its own street number. It would be chaos, the numbers would be so big you would easily get lost. The same happens on the internet. There are just not enough numbers.

This is called a NAT. Network Address Translation. You have a main public address that gets translated into private blocks.

Are we out of IP’s yet?

Yes and no. In theory the RIR’s or Regional internet registers are in charge of delivering IP blocks. At first, they could only divide blocks in three classes.

Class A ( /8 block)

Examples of A Blocks: – (Around 16 million addresses)

Class B ( /16 ) This looks like this – ( 65 thousand addresses)

Class C ( /24 ) This looks like this – (256 addresses )

ip address

This task was given to IANA (Internet assigned numbers authority)

This was done just for the ease of it. Not with efficiency in mind. So if you needed 500 addresses, you were given a class b block of 65 thousand. This is something you obviously do not need. It was just throwing away IP’s. Equally if you needed 66 thousand addresses you were given 16 million!

No one ever thought there would ever bee a need for 4 billion addresses. We still feel that mistake now a days. As companies who got it early on are not forced neither do they have a good reason to give up their IP space. Resulting in thousands of addresses being just unused. The early blocks do not comply with the regulations from now a days, where a percentage of your allocated space must be used.

That until recently. As we run out of space and universities like the MIT have /8 blocks have been incentivized by the sale of IP blocks. An IP sells on the market for around 20$, in bulk that number might be around 10$

Let’s say the MIT decides to sell it’s /8 space, resulting in 160 million dollars in profits. And indeed it is selling some of it’s space. Check out more here

So in reality we are not out of ip blocks, they are just on the wrong hands. The department of defense of the US holds the largest amount of IP space at 201 million addresses or 12 blocks. That is the number of ip’s china has right now.[2]

Even if each soldier in the US had their own address, that would leave us with around 100 ip’s per soldier. Imagine that.

The world is an unfair place, now what?

IP Exhaustion solutions

How is the world dealing with the IP exhaustion? We are surely smart enough to get by and use it as much as possible right? Yes indeed. We have created solutions such as NAT’s, IP Sell and breaking up IP blocks.


In the NAT space, many providers, mine included, are creating massive NAT’s in regions. This means my entire neighborhood of around 10,000 people are assigned private addresses instead of public ones. This entire region uses only one IP which then distributes it to your router, which then has another nat that distributes it in your house. While an intelligent solution, it is just a temporary fix as this comes with a lot of limitations.

You do not get to chose which ports you want open and which ones you want closed.

This means you can not host your own website on your router, you might have gaming trouble, you can not access your home network from the outside directly if some ports are closed. Not good right?

Security concerns

If done improper by the ISP’s it might be harder to identify each user on the network.

IPv4 Market

As I mentioned earlier, big unused IP blocks are being broken up. There was a bill in the US for the DoD to sell it’s entire IP blocks and change completely for IPv6. That would surely satisfy IPv4 demand for around 5 years. But this is also an issue, as an IP block needs a gateway, broadcast address, etc… So in reality a /24 block instead of having 256 ip’s it has now 254. So two IP less. Now an /8 block has around 1.6 million /24 blocks, rendering 3.2 million addresses unusable if broken up irresponsibly. As much as it might be a solution, it is also a concern for many RIR’S.

IPv6 – Conclusion

Although we are nowhere near the massive implementation of IPv6, we are in progress of doing so. Many ISP’s now use IPv6 to IPv4 translations that might ease the problem. The IPv6 has a lot more ip addresses which for now, does not seem a concern. But think about it, we thought IPv4 would never have an end. Maybe we will deplete IPv6 in some years? Is IPv6 being wastefully deployed? Why not provision smaller blocks like /128 and /120’s so this does not happen again? Right now providers are given the minimum space of /32 blocks.

But that is not any of our concern. At least for the next 100 years or more. Just like the IPv4 creators thought.

Now that you know, check this out, opinion from the experts!