Comment by spauldo
14 hours ago
A large chunk of IT people don't understand it. So they don't demand it from their vendors. The vendors see the lack of demand so they spend fewer resources on it. When someone wants to implement IPv6, they see the limited vendor support and decide against it.
The last three companies I've worked at have all been IPv4 only. I set up IPv6 in our lab, but neither the SCADA software nor the PLCs we use support it at all, and none of my coworkers can troubleshoot it if problems pop up.
I've got a buddy that's a technical manager at an ISP and he'll straight up tell you they don't do IPv6 because he and his people don't know it.
Yep. I run into "enterprise" cloud environments where IPv6 is disabled, all the time. The sad thing is IPv6 is easier to understand than v4, just based on subnetting practices alone. The real problem is the average "IT" person doesn't understand hexadecimal.
Thing is, you can run ipv4 only, dual stack or ipv6 only. Ipv6 only won't work. Dual stack has a larger attack surface and is complex. Ipv4 works but costs a relatively tiny bit of money so far.
Why would you not use ipv4?
It's definitely a slight learning curve (a few days at most for basic understanding and troubleshooting). I can't speak to complexities like routing protocol configurations.
But goodness, the infinite-subnets-of-same-size glitch is so amazing. I see companies all the time that struggle to subnet their sprawling enterprise. Different subnet sizes everywhere, fragmented networks, subnet migrations to try to defragment, so on.
Many orgs are so short-staffed and staffed with mediocre talent that they spend their days fighting fires and keeping their flawed current practices operating just well enough to keep the lights on and not cause outages or security breaches. Things like "optimizations" and "redesigns" of the IP stack, even in 2026, would be a 5-10 year journey without a dollar sign benefit attached to it. So they limp along until the transition is seamless and necessary or monetarily desireable.
It's only really a learning curve if you're an expert at IPv4, and try to apply your IPv4 mental model directly to IPv6.