IPv6 and the VCR

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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.

 Tom’s Take

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.

10 thoughts on “IPv6 and the VCR

  1. I think the IPv6 transition story breaks down right here: “As these new systems are brought online, IPv6 will be the only address space available.” This has the logical fallacy that IPv6 are equivalent to IPv4 addresses. Everyone knows that this isn’t true, but when they tell this story they just assume that a company is going to give up on connecting to 99.9% of the internet and settle for connecting to .1% of the Internet. And Metcalfe law states that these clearly don’t have the same value.
    Now you’ve say everyone just has to do the greater good and go dual stack first. But Game theory, and history would suggest people aren’t going to do this.
    Oh, we’ll just 6to4 NAT in the interim then. Well if would seem if NAT can fix the problem 4to4 NAT is easier, & more proven (also likely cheaper).

    My opinion (not that of my employer) is that public IPv4 address should be priced and marketed like that rare precious resource that they are, because it is a myth (that won’t die) that every device should have a public IP address.

    • I do think you’re right. The key driver in IPv6 adoption has been cost. IPv4 has been cheap to acquire and easy to support. IPv6 has required additional resources and effort to implement. Because IPv6 was always designed to be deployed in parallel to IPv4 during transition and no additional benefit was apparent for cost, it wasn’t deployed.

      I like the idea of treating IPv4 as a scarce, expensive resource. By raising the price of v4 address adoption, we can make IPv6 a more palatable option. Having enough address space to connect a country is one thing. But making the alternative an expensive exercise in futility is a much more likely selling point.

      • But if you also open up the market for expensive IPv4 to be sold, you incentivize people to not hoard them, freeing up space for devices that really need to be public. But this is a world and NAT and IPv4 and continuing that world is something the pro-IPv6 crowd want. They seem to want IPv4 wither on the vine to encourage IPv6 adoption. And I think this comes from a deep core belief that NAT is bad and every device should have a globally unique address.

        The idea of a core need of global uniqueness for addressing hasn’t been proven but I feel really underlines the whole IPv6 messaging.

        No I’m not one that says NAT = security, BTW. But I don’t believe that the cost of switching to IPv6 is worth the benefit of global uniqueness in addressing. Why does my Nest Thermostat or FitBit bathroom scale need a globally unique address?

  2. IPv6 has become a complete and utter failure; not due to the technology itself, but rather it’s adoption.

    Sixteen years into the RFC, and there’s still a 4% adoption rate. Not even the Denver Broncos failed that bad in this year’s Super Bowl.

    And the sad reality is, it’s still an afterthought for vendors. ‘Get the device out the door with IPv4, and later kick in a patch to allow IPv6. If they complain, tell them about GRE tunnels’. Unacceptable.

    • Complete and utter failure? I cannot agree… Titanically slow to deploy, and ignored by many, yes…

      There is a much larger IPv6 user base then most people realize. I’d bet a large portion of the readership of this blog have an IPv6 enabled device and don’t even realize it. If you have a modern smartphone or tablet with LTE try this: Disable wifi and then google ‘whats my ip address’ in your mobile browser. If your phone is on LTE the address you see should be an IPv6 address. According to some stats I found on LTE adoption, there were about 80 million LTE devices in 2013.

      The IPv6 clients are there now and growing rapidly, its the content providers that are still a bit slow to start providing services via IPv6 to their customers. If you serve it, they will come…

  3. There will always be people attached to any legacy system, like IPv4. Share may be just 4% now, but look at the growth curves and Google and Cisco projections. Within network operators and data centers it is a necessity, as in wireless broadband. For home and small business users interested in gaming or hosting a server it will be a necessity to avoid CGN that breaks port forwarding. Marketers will push for IPv6 so that they can better understand customers, rather than just seeing IPv4 addresses of tunnel endpoints. Many organizations will keep IPv4 addresses, but also upgrade to IPv6. Over time, a shorter time than some of the commenters above seem to think, IPv6 will predominate. Why pay higher and higher costs for additional, scarce IPv4 addresses when most services can easily migrate to IPv6?

  4. “I think it’s important for people in tech to know that IPv6 isn’t displacing IPv4”

    I think its also important for people in tech to know IPv6 isn’t optional. Its already in your network, and if you don’t learn to manage IPv6 it becomes a risk. Ed made this point at Interop in his IPv6 session.

    For example: Have a VPN with a non-split routing policy where all traffic goes through the VPN? Have you checked whether it applies to IPv6? I’ve personally seen a non-split VPN fail to enforce that policy for IPv6 by default, so a client can get IPv6 connectivity directly to the internet and IPv4 into your corporate network over the VPN. Your security officers might be apoplectic about that.

  5. At current IPv4 prices, CGN>IPv6 in terms of business case. What’s the incentive to spend money now to capture zero more eyeballs? Because that’s how many eyeballs there are out there who are only running IPv6. The 4% traffic figure (a little high) for IPv6 comes from dual-stacked hosts for the most part. Nobody will be content, currently, with only an IPv6 connection. So nobody has one and nobody is losing business for lack of IPv6. What is the motivation for change, outside the technical superiority of IPv6? That wasn’t enough for Sony Beta, to continue the author’s videotape analogy. The Internet is an entity on its own, now, that responds primarily to market forces. Those forces will take the path of least resistance, which is CGN, or some form of conversion of native Ipv6 to Ipv4, which will probably be more expensive than simple 4to4 Natting.
    The valid points about IPv6 security risks provide the incentive to turn off IPv6 in the enterprise, in the current failed-transition environment.

  6. Pingback: It’s Time For IPv6, Isn’t It? | The Networking Nerd

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