Nibbles & Bits

Podcast Summary-The Problem With IPv4 Thinking

by | August 19, 2022

After years(decades?) of being programmed to work with IPv4, there are telltale signs that you might have fallen victim to a dangerous syndrome called “IPv4 thinking.” Thankfully, not only are there tests to assess if you have this syndrome, but there is a popular antidote on the market to reverse the symptoms. That antidote is shifting to IPv6.

Unlike physical ailments, IPv4 thinking isn’t harmful to your personal health. Unless we compare IPv4 scarcity to a lego block that you’re just about to step on “ouch” in this case it can be a pain. Either way, it is something to be aware of, however, when it comes to IPv6 migration efforts.

In this episode of Packet Pushers IPv6 Buzz 102 Tom Coffeen, Scott Hogg, and Ed Horley talk about the nearly unnoticeable ways IPv4 thinking has become so limiting (and problematic). But first, they address what IPv4 thinking is, how it’s detrimental to IPv6 address planning, how it can impede IPv6 design, and much more.

What Is IPv4 Thinking?
Listening to the hosts individually answer the basic question of “What is IPv4 thinking?” sounds like the equivalent of an IT comedy roast. Each one has a different take on how to define IPv4 thinking, which include:

  • “It’s the idea that you have a limited amount of IPv4 space.”
  • “It’s a foreboding feeling that you‘re running out, like you’re running faster and faster and hustling, but not getting anywhere.” 
  • “It’s wondering if a new requirement will rear its ugly head.”
  • “Everything is crumbling before you, when your wonderful design is going out the window.”

If you can confirm that you’ve had those same thoughts and experiences in your past work, you might be in an IPv4 thinking recovery period. It’s especially important to be aware of IPv4 thinking because it can have a detrimental impact on IPv6 address planning.

Detrimental Effects of IPv4 Thinking
How so? One way to tell if IPv4 thinking will have a detrimental effect on your IPv6 design is in your initial assessment. If you’re someone whose initial thoughts during the architecture and design phase revolve around host address consumption with IPv6, you’re likely still in the IPv4 mindset. You might think you’re working on an IPv6 project, but you’re stuck in IPv4, and that will negatively impact your design. As a matter of fact, in a previous discussion on Containers and IPv6, Ed Horley explains this well, “to consume a single /64 of address space on a single Docker host that is generating 10 million containers per second it would take more than 58 thousand years to consume all the IPv6 addresses.” So thinking you have limited IPv4 space should be eliminated.

“Instead, you should be thinking about IPv6 prefix consumption.”

Can IPv4 Thinking Impede Design, Architecture, and Operations?
In fact, when too much IPv4 thinking has taken place, the design phase of IPv6 is where network engineers will pay the biggest penalty. With IPv4 limitations driving data center architecture and WAN architecture, for example, layering on the veneer of IPv6 becomes unnatural because it doesn’t fit. It can be like trying on a shoe, thinking that using a shoehorn will help, but the shoe wasn’t actually the right size. You can’t force it, unless you want to deal with the pain of foot problems down the line. In that same way, the physical topology of IPv4 wasn’t meant to be coupled with IPv6.

It is not uncommon for network engineers to be asked to represent characteristics of an IPv4 address space into their IPv6 design. The truth is, there are negative outcomes to tightly coupling IPv4 and IPv6 together when they don’t need to be.

“It’s the mother of all mistakes where IPv4 thinking is concerned.”

In reality, coupling IPv4 and IPv6 leads to constraints in the security design model, thought process about how logical entities should be broken up, underlays, overlays, and all sorts of architecture design issues. You immediately constrain yourself to the IPv4 way of doing things, including the size and bound of a network.

As the episode comes to an end Tom, Scott and Ed share their final thoughts. Recognizing that the goal is to make IPv4 go away, the good news is that IPv4 thinking is completely curable with the correct approach. Separate IPv4 and IPv6 into their respective parts, and don’t drag IPv4 thinking into your next IPv6 design. Constantly test yourself to make sure you’re not limiting your design based on ideas you’ve brought with you from previous programming.

Wipe the slate clean. Imagine you don’t know anything about IPv4 and start with IPv6 cleanly – that’s the best way to cure IPv4 thinking.

Don’t want this discussion to end? Check out IPv6 Buzz to find more episodes surrounding this topic.

“We decided to move our rather complex IP address and DHCP management process to ProVision and it has worked out great for us!! The team at 6connect were very flexible and went above and beyond to accommodate our requirements and helped to make the migration as smooth and hitch free as possible. Kudos to the team @ 6connect!”

Premkumar Subramaniam
Head of R&D

“We are excited to be partnering with 6connect to leverage their technology and talent. We particularly admire their long-standing IPv6 contributions and their ability to service and support customers in this area, some who are the largest service provider in the world. The 6connect executive leadership team and technical team are great to work with and we look forward to many partnered projects to help customers address their Cloud, IoT and Security needs with IPv6. Automation, workflow and orchestration are critical to the success of most of these projects and 6connect is well positioned to help our mutual customers in those areas.”

Ed Horley
Co-Founder & CEO

“Enterprises can struggle managing purposefully segmented DDI architectures with any agility. Our partnership with 6connect empowers customers with complex infrastructures to move faster to service the business while consolidating visibility and control over their estate.”

Andrew Wertkin
Chief Strategy Officer,

“6connect’s approach to automation addresses quite a few challenges with physical and virtual networks – how to improve the agility of your current network infrastructure without sacrificing reliability and adoption of future network technologies.”

Pär Lange
Investment Director

“A customer is looking for an integrated solution from a single vendor for both IPAM and DNS. Through the 6connect reseller program, Secure64 is able to offer the most secure DNS solutions married to a unique combination of IPAM and resource provisioning that customers want. It’s a marriage made in heaven.”

Mark Beckett
VP of Marketing

“A huge benefit of working with the 6connect team is that they devoted a lot of resources to get our products integrated so we had the turnkey solution that we could take to market. It was very easy to work with their team to get product integrated and successfully launched.”

Mark Beckett
VP of Marketing

You have IPv6!

You’re on IPv4.

Explore ProVision Suite

Resource Controller



DHCP Controller

Peering Controller


Talk to one of our Engineers