If you haven’t learned IPv6 yet, well, you’re not the only one. In December 2016, IPv6 (as we know it today) turned 18 years old. Children who were in the womb when RFC 2460 was being drafted are now old enough to vote, get married, and purchase firearms in some states.
In honor of IPv6’s 18th birthday, allow me to share my theories on why people have been so slow to adopt it. And why you still should consider learning it.
The “Lame name” theory
The “Let’s split DHCP in half and spread its most popular functions across two protocols” theory
DHCP for IPv4 can provide clients with IP addresses, DNS servers, default gateways, TFTP servers, and pretty much anything else. DHCPv6 doesn’t have an option for providing a default gateway. If you want to push a default gateway to clients, you have to use SLAAC.
The “all things to all people, places, animals, plants” theory
IPv4 has only a few address types that anyone actually uses. Colloquially, they’re public, private (RFC 1918 addresses like 192.168.1.1), and multicast (which includes broadcast). IPv6 has approximately one zillion different address types, including unique-local, link-local, unspecified, and global unicast. Although there are technical justifications for some of these, the plethora of address types makes no sense to anyone who doesn’t deeply understand why “layer 2” is even in the IT lexicon.
The “IPv4 apocalypse” theory
We’ve all heard the constant chicken-little talk about how we have to move to IPv6 yesterday or the internet will die. Driving this is the myth that all IPv4 addresses are gone. They’re not, and the U.S. government is sitting on tens of thousands it’s never going to use. What really happened was that in 2011, the Internet Assigned Numbers Authority (IANA) assigned the last of its available IP address space to regional internet registries (RIRs) which are responsible for doling out addresses. But the IPv4 addresses didn’t just go away. They still exist, and many of them are unused and can be reassigned.
The “NAT is a tool of the devil” theory
If you ever want to have fun, go on any IT forum and ask, “Why do we need IPv6 when we have NAT?” Actually, don’t. That would be trolling. But if you were to ask that question, you’d probably get a few responses hating on IPv4 NAT as a tool of the devil, which IPv6 will save us from… except it does NAT, too.
The “Why do I need both again?” theory
Implementing IPv6 almost always requires a multihomed (dual-stack) implementation, which people figured out about 30 years ago was a bad idea with IPv4 because it confuses everybody. IT admins translate this as, “More work for me.”
The “Because we can” theory
There are enough IPv6 addresses for every cell in your body to have its own internet. Seriously? This, like NAT, is another non-reason to adopt it. Yes, it’s cool that I can give my Uncle Milton’s ant farm its own Internet. But as far as business justification goes, nope.
Why you might want to learn IPv6 (hint: money)
Although it’s been poorly marketed, it’s still worth learning. In fact, I believe in IPv6 so strongly that I’ve created several Pluralsight courses on configuring and troubleshooting it.
Here are three big reasons to consider adding it to your set of skills:
- It’s like a sports team. The big boys are rooting for it. I’m talking about Cisco, Juniper, ISPs, Google, et alia. They want to see it win, and they’ll pay to make it happen. You can be on the receiving end of some of those payments.
- The confusion and complexity around IPv6 has made experts that much more valuable to companies who have already invested in new infrastructure.
- If you know IPv4, IPv6 isn’t that hard to learn once you realize that it’s a distinct protocol and not a new version of IPv4.
For further IPv6 learning, check out my _Practical Networking_ course.