IPv6 isn’t a fad. It’s not a passing trend that will be gone tomorrow. When Vint Cerf is on a nationally televised non-technical program talking about IPv6 that’s about as real as it’s going to get. Add in the final depletion of IPv4 address space from the RIRs and you will see that IPv6 is a necessity. Yet there are still people in tech that deny the increasing need for IPv6 awareness. Those same people that say it’s not ready or that it costs too much. It reminds me of a different argument.
My house is full of technology. Especially when it comes to movie watching. I have DVRs for watching television, a Roku for other services, and apps on my tablet so the kids can watch media on demand. I have a DVD player in almost every room of the house. I also have a VCR. It serves one purpose – to watch two movies that are only available on a video tape. Those two movies are my wedding and the birth of my oldest son.
At first, the VCR stated connected to our television all the time. We had some movies that we owned on VHS that we didn’t have DVD or digital copies. As time wore on, those VHS movies were replaced by digital means. Soon, the VCR only served to enable viewing of the aforementioned personal media. We couldn’t get that on a DVD from just anywhere. But the VCR stayed connected for those occasions when the movies needed to be watched. Soon, it was too much of a hassle to reconnect the VCR, even for these family films. Eventually, we figured out how to hook up the VCR and record the content into a digital format that’s available from non-analog sources.
How does this compare to IPv6? Most people assume that the transition to IPv6 from IPv4 will be sudden and swift. They will wake up one morning and find that all their servers and desktops are running global IPv6 addresses and IPv4 will be a distant memory. In fact, nothing can be further from the truth. IPv4 and IPv6 can coexist on the same system. IPv6 can be implemented alongside IPv4 without disrupting connectivity. As in the above example, you can watch DVDs and VHS tapes on the same TV without disruption.
As IPv4 address availability is restricted, may engineers will find themselves scrambling to replace existing systems and deploy new ones without access to IPv4 addresses. That’s when the real cutover begins. As these new systems are brought online, IPv6 will be the only address space available. These systems will be connected with IPv6 first and provisions will be made for them to connect to other systems via IPv4. Eventually, IPv4 will only exist for legacy systems that can’t be upgraded or migrated. Just like the VCR above, it will only be needed for a handful of operations.
We never have to reach a point where IPv4 will be completely eliminated. IPv4-only hosts will still be able to connect to one another so long as the global IPv4 routing table is available. It may be reduced in size as IPv6 gains greater adoption, but it will never truly go away. Instead, it will be like IBM’s SNA protocol. Relevant to a few isolated hosts at best. The world will move on and IPv6 will be the first choice for connectivity.
I must admit that this idea was fostered from a conversation with Ed Horley (@EHorley). The evangelism that he’s doing with both the CAv6TF and the RMv6TF is unparalleled. They are doing their best to get the word out about IPv6 adoption. I think it’s important for people in tech to know that IPv6 isn’t displacing IPv4. It’s extending network functionality. It’s granting a new lease on life for systems desperately in need of address space. And it allows IPv4-only systems to survive a little while longer. You don’t have to watch the same old VHS tapes every day. But you don’t have to leave the IPvcr4 hooked up all the time either.