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The collapse in IPv4 transfer prices is what caught my eye here, dropping from a ~$55 peak in 2021 to a mean of $22 in early 2026 (figure 12). This validates m

The collapse in IPv4 transfer prices is what caught my eye here, dropping from a ~$55 peak in 2021 to a mean of $22 in early 2026 (figure 12). This validates my hypothesis that the run-up in 2020–2022 was an artificial scarcity bubble driven largely by hyperscalers. AWS was right up there stockpiling before they shifted their pricing model. Once AWS introduced the hourly charge for public IPv4 addresses (effectively passing the scarcity cost to the consumer), their acquisition pressure vanished. The text notes Amazon stopped announcing almost 15M addresses in Nov 2025. I think they have moved from aggressive accumulation to inventory management. We are seeing asset stranding in real-time. The market has realized that between the AWS tax and the efficacy of mobile CGNAT, the desperate thirst for public v4 space was not infinite. I'm curious to hear more takes on this.

zokier 9mo ago
It is noteworthy that in 2020 AWS had very limited ipv6 support, but these days they have at least some support in the most critical services.
newsoftheday 9mo ago
When AWS rolled out plans to start charging for IPv4 addresses: https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/ https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address... "As you may know, IPv4 addresses are an increasingly scarce resource and the cost to acquire a single public IPv4 address has risen more than 300% over the past 5 years. This change reflects our own costs and is also intended to encourage you to be a bit more frugal with your use of public IPv4 addresses and to think about accelerating your adoption of IPv6 as a modernization and conservation measure." Their move disgusted me and I moved from AWS to OCI.
- knollimar 9mo ago
  What disgusted you about it? I'm out of the loop
  - jdsully 9mo ago
    They hadn't bothered to add ipv6 support to most of their services and the ones that did have it usually were only dual stack - still requiring an ipv4 address.
    - knollimar 9mo ago
      That sounds like a failure in every direction. I see why you moved
    - huslage 9mo ago
      They didn't require you to have a public IPv4 address. Just an IPv4 address.
      - pixl97 9mo ago
        Which requires dual-stack and all the issues that come with it, especially with private addresses.
  - newsoftheday 9mo ago
    It was clearly a corporate money grab, not an altruistic motion as they made it sound.
dlcarrier 9mo ago
As someone with a background in electronics who doesn't manage any internet-connected equipment but has multiple embedded devices connected to a WAN, I'm glad that IPv4 still seems to have a bit of life left in it. When IPv6 was developed, over 30 years ago, connecting everything to the internet seemed like a great idea. I know that IPv6 can be made secure, but I don't have the background or research time to learn how to do so, and the NAT-by-default of IPv4 effectively means that I get the benefit of a default-deny security strategy that makes it impossible to accidentally directly connect anything to the internet. I'm hoping I can keep using IPv4 until IPv8 or IPv4.5 or whatever comes next is developed with the modern proliferation of cheap insecure IoT in mind. For some background on why IoT products are so insecure: Hardware manufacturers don't really comprehend the idea of updates, let alone timely of security patches. Hardware has to work on the day of release, so everything is documented and tested to verify it will work. I have hardware with a TCP/IP stack that was released 20 years, (https://docs.wiznet.io/Product/Chip/Ethernet/W5500 https://docs.wiznet.io/Product/Chip/Ethernet/W5500) and doesn't have a single errata published, despite widespread use. This is expected for every single component, for even the smallest 1-cent transistor, which has dozens of guaranteed performance characteristics laid out over several pages of documentation (https://en.mot-mos.com/vancheerfile/files/pdf/MOT2302B2.pdf https://en.mot-mos.com/vancheerfile/files/pdf/MOT2302B2.pdf). When manufacturers venture into a product that runs software, they don't realize that for a given complexity, working through undocumented or, worse yet, incorrectly documented APIs takes more time than the equivalent hardware development and documentation. I've worked on multiple projects where software bugs were fixed with hardware workarounds, because it's faster, cheaper, and easier to develop, test, document, retool, and add a few cents of bill-of-materials cost per product, than to get reliable output from the already-written library that's supposed to provide the functionality. The hardware TCP/IP stack that I linked to was developed at a time when it was the cheapest way to connect a low-power embedded system to a network. Modern low-power embedded systems have multiple cores running at hundreds to thousands of MIPS making the resources to run a softtware TCP/IP stack trivial, but the product still sells well, because when security is an absolute must, the hardware development and maintenance cost for the functionality is still cheaper than through software, even when there's no marginal cost to run the software.
- radlad 9mo ago
TNorthover 9mo ago
[dead]
inemesitaffia 9mo ago
Amazon LEO Aka Kuiper >stopped announcing almost 15M addresses in Nov 2025
JulianHart 9mo ago
The CGNAT point is underrated. Carriers have zero incentive to move away from it - thousands of users per public IP, no transition cost. The interesting downstream effect is on IP reputation systems. Traditional detection assumed 1 IP = 1 user. CGNAT breaks that entirely - platforms can't aggressively filter mobile carrier IPs without blocking legitimate customers by the thousands. Makes sense the IPv4 price dropped once mobile networks proved you can serve massive user bases with relatively few public addresses.
- wcfields 9mo ago
  Anecdotally on how this affects the day to day user experience: I just deployed T-Mobile 5G Business Internet to a temporary pop-up art space (it's only active for a few months) and I'd say twice daily I get a CAPTCHA challenge on Google search.
  - pixl97 9mo ago
    And I hope it gets worse for users behind CG-NAT to the point that websites and ISPs move to IPv6.
  - kalleboo 8mo ago
    I would have thought that a 5G connection would have IPv6 and wouldn't need CGNAT to Google properties
- patmorgan23 9mo ago
  Expect CG-NAT boxes are expensive, and introduce another point of failure into the network. Most mobile carriers are running IPv6 first networks these days anyway. Like you said, CG-NAT does have the benefit of making v4 address reputation less reliable, which means it's not as big a deal for the transition to v6.
  - pixl97 9mo ago
    >CG-NAT does have the benefit of making v4 address reputation less reliable heh, less reliable is doing a lot of heavy lifting there. You mean "complete and total trash". We need to get to the point where Cloudflare/AWS/some other big sites just block CG-NAT nodes for a day going this IP address is a risk. Instead if you're a website, instead of doing an easy block by IP, you're left filtering out AI crawlers, spammers, and lots of other crap hiding behind a single IP with thousands of other users behind it, and ISPs that don't really give a shit about doing anything about it. We need to push the value of IPv4 to nearly zero and finally move away from that crap.
WorldMaker 9mo ago
> efficacy of mobile CGNAT At driving the majority of mobile traffic to IPv6? Otherwise, it seems hard to describe mobile CGNAT as efficacious to me.

zokier 9mo ago

It is noteworthy that in 2020 AWS had very limited ipv6 support, but these days they have at least some support in the most critical services.

newsoftheday 9mo ago

When AWS rolled out plans to start charging for IPv4 addresses: https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/ https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address... "As you may know, IPv4 addresses are an increasingly scarce resource and the cost to acquire a single public IPv4 address has risen more than 300% over the past 5 years. This change reflects our own costs and is also intended to encourage you to be a bit more frugal with your use of public IPv4 addresses and to think about accelerating your adoption of IPv6 as a modernization and conservation measure." Their move disgusted me and I moved from AWS to OCI.

knollimar 9mo ago
What disgusted you about it? I'm out of the loop
- jdsully 9mo ago
  They hadn't bothered to add ipv6 support to most of their services and the ones that did have it usually were only dual stack - still requiring an ipv4 address.
  - knollimar 9mo ago
    That sounds like a failure in every direction. I see why you moved
  - huslage 9mo ago
    They didn't require you to have a public IPv4 address. Just an IPv4 address.
    - pixl97 9mo ago
      Which requires dual-stack and all the issues that come with it, especially with private addresses.
- newsoftheday 9mo ago
  It was clearly a corporate money grab, not an altruistic motion as they made it sound.

dlcarrier 9mo ago

As someone with a background in electronics who doesn't manage any internet-connected equipment but has multiple embedded devices connected to a WAN, I'm glad that IPv4 still seems to have a bit of life left in it. When IPv6 was developed, over 30 years ago, connecting everything to the internet seemed like a great idea. I know that IPv6 can be made secure, but I don't have the background or research time to learn how to do so, and the NAT-by-default of IPv4 effectively means that I get the benefit of a default-deny security strategy that makes it impossible to accidentally directly connect anything to the internet. I'm hoping I can keep using IPv4 until IPv8 or IPv4.5 or whatever comes next is developed with the modern proliferation of cheap insecure IoT in mind. For some background on why IoT products are so insecure: Hardware manufacturers don't really comprehend the idea of updates, let alone timely of security patches. Hardware has to work on the day of release, so everything is documented and tested to verify it will work. I have hardware with a TCP/IP stack that was released 20 years, (https://docs.wiznet.io/Product/Chip/Ethernet/W5500 https://docs.wiznet.io/Product/Chip/Ethernet/W5500) and doesn't have a single errata published, despite widespread use. This is expected for every single component, for even the smallest 1-cent transistor, which has dozens of guaranteed performance characteristics laid out over several pages of documentation (https://en.mot-mos.com/vancheerfile/files/pdf/MOT2302B2.pdf https://en.mot-mos.com/vancheerfile/files/pdf/MOT2302B2.pdf). When manufacturers venture into a product that runs software, they don't realize that for a given complexity, working through undocumented or, worse yet, incorrectly documented APIs takes more time than the equivalent hardware development and documentation. I've worked on multiple projects where software bugs were fixed with hardware workarounds, because it's faster, cheaper, and easier to develop, test, document, retool, and add a few cents of bill-of-materials cost per product, than to get reliable output from the already-written library that's supposed to provide the functionality. The hardware TCP/IP stack that I linked to was developed at a time when it was the cheapest way to connect a low-power embedded system to a network. Modern low-power embedded systems have multiple cores running at hundreds to thousands of MIPS making the resources to run a softtware TCP/IP stack trivial, but the product still sells well, because when security is an absolute must, the hardware development and maintenance cost for the functionality is still cheaper than through software, even when there's no marginal cost to run the software.

radlad 9mo ago

TNorthover 9mo ago

[dead]

inemesitaffia 9mo ago

Amazon LEO Aka Kuiper >stopped announcing almost 15M addresses in Nov 2025

JulianHart 9mo ago

The CGNAT point is underrated. Carriers have zero incentive to move away from it - thousands of users per public IP, no transition cost. The interesting downstream effect is on IP reputation systems. Traditional detection assumed 1 IP = 1 user. CGNAT breaks that entirely - platforms can't aggressively filter mobile carrier IPs without blocking legitimate customers by the thousands. Makes sense the IPv4 price dropped once mobile networks proved you can serve massive user bases with relatively few public addresses.

wcfields 9mo ago
Anecdotally on how this affects the day to day user experience: I just deployed T-Mobile 5G Business Internet to a temporary pop-up art space (it's only active for a few months) and I'd say twice daily I get a CAPTCHA challenge on Google search.
- pixl97 9mo ago
  And I hope it gets worse for users behind CG-NAT to the point that websites and ISPs move to IPv6.
- kalleboo 8mo ago
  I would have thought that a 5G connection would have IPv6 and wouldn't need CGNAT to Google properties
patmorgan23 9mo ago
Expect CG-NAT boxes are expensive, and introduce another point of failure into the network. Most mobile carriers are running IPv6 first networks these days anyway. Like you said, CG-NAT does have the benefit of making v4 address reputation less reliable, which means it's not as big a deal for the transition to v6.
- pixl97 9mo ago
  >CG-NAT does have the benefit of making v4 address reputation less reliable heh, less reliable is doing a lot of heavy lifting there. You mean "complete and total trash". We need to get to the point where Cloudflare/AWS/some other big sites just block CG-NAT nodes for a day going this IP address is a risk. Instead if you're a website, instead of doing an easy block by IP, you're left filtering out AI crawlers, spammers, and lots of other crap hiding behind a single IP with thousands of other users behind it, and ISPs that don't really give a shit about doing anything about it. We need to push the value of IPv4 to nearly zero and finally move away from that crap.

WorldMaker 9mo ago

> efficacy of mobile CGNAT At driving the majority of mobile traffic to IPv6? Otherwise, it seems hard to describe mobile CGNAT as efficacious to me.