On Mon, Jul 4, 2016 at 7:44 AM, Matt Hoppes < mattlists@rivervalleyinternet.net> wrote:
I disagree. Any data center or hosting provider is going to continue to offer IPv4 lest they island themselves from subscribers who have IPv4 only - which no data center is going to do.
Thus, as an ISP you can safely continue to run IPv4. Ipv4 won't be going away for at least ten years or more - if ever.
That's an interesting "bet the business" decision for an ISP to make. It's not one a large ISP can make simply because they want to continue growing their subscriber base and that's a losing proposition as far as profits go. That's why all the big ISPs are either implementing IPv6 or actively working to deploy it. So it seems you're saying that a small to medium sized ISP can delay 10 or more years because all the content their customers want will be available over IPv4. And that's pretty much betting the entire business on what is basically nothing more than a crystal ball. I don't know about you, but I think back to the mid to late 80s and most ideas I saw about where technology would be by the mid to late 90s were pretty inaccurate. Jump to the mid 2000s and past projections were pretty off-base again. Shortly after that, mobile computing really hit and the world today looks very little like it did then. Do you really think someone should bet their entire business on your ability to make Internet forecasts 10 years into the future? Now, that's not to say I expect IPv4 to necessarily be mostly gone (from the Internet, not private networks) in 10 years, though it wouldn't particularly shock me either if things did work out that way. But I do expect a tipping point will be reached well before then that reduces the utility of IPv4. Technology changes on the Internet have not traditionally been steady, gradual processes. Rather, they've had some sort of fairly long lead time, a rapid spike of uptake, and then a flip from a 'new' technology to something expected. There's then often something of a long tail, but it can be pretty unpleasant to be forced to exist in that tail. The attitude quickly switches to one of, "Oh, you're still using 'x'? You should use 'y' instead. It's working fine." And issues with 'x' get lower priority attention. And that 'flip', when it happens, tends to happy relatively quickly. Often, it can be difficult to predict if a new technology will overtake and supplant an older one. The IPv6 transition, however, is being forced by IPv4 exhaustion. That's putting a lot of technological and financial pressure on most of the parties involved. As someone who works at an enterprise that sees a lot of traffic, primarily from the US, we were seeing a steady increase in IPv6 traffic from end users from practically nothing in 2012 to around 15% in 2015. This year we've seen it spike to 25%-30%. So in the US, we may very well reach that tipping point within the next couple of years. If we do, the utility of IPv4 will probably start to degrade pretty rapidly as more attention and focus is placed on IPv6 connectivity. If that happens and you're still an IPv4 only edge/access network that hasn't even begun planning an IPv6 deployment? That's apt to be an uncomfortable experience. But again, I'm not a prognosticator. I wouldn't have correctly guessed the timing for any of the transitions I've seen in the past, though I did sometimes come close to guessing the outcome. (That's one of the reasons I started a small scale production deployment of Linux at my place of employment back in the mid-90s, something we now have running on platforms all the way up to our mainframes.) It looks to me like, in the US at least, we're on the 'rapid uptake' slope of adoption. If that's the case, then that tipping point is probably coming a lot sooner than 10 years out. You could be right and everything will be fine for IPv4-only customers and networks in 10 years. But that is most definitely a high stakes bet to make. I certainly wouldn't be willing to make such a gamble. I also want to note that enterprise or data center networks moving to IPv6 only does not necessarily involve NAT64 or any sort of translation. For any large internet service, inbound connections are typically terminated at the edge. A new connection is then established from the point of termination to the data center resources. So Facebook, for instance, only needs to dual-stack its edge. And if you use a 3rd part CDN for the edge, you don't even have to do that. That's what other posters were pointing out. Depending on its security profile, a large enterprise network might also 'proxy' outbound Internet traffic (primarily web, mail, DNS) already for its internal users. If that's the case (as it is where I work) very little outbound translation is required as well and only the outbound perimeter services need to be dual-stacked long-term. So if an enterprise or data center network operator isn't already thinking in terms of where they can go IPv6 only rather than dual-stacked, now is probably when you want to start thinking that way. There is a definite cost to trying to operate what is essentially two networks over the long haul. The more places you can move from dual-stacked to single-stacked IPv6 in your network, the better off you'll be. And even ISP access networks are moving more toward offering IPv4 as a service on top of a native IPv6 network. T-Mobile is already doing that.
From what I've seen, others are exploring ways to do it. Especially given all the constraints on IPv4, that approach just makes sense.
So again, the safe bet today looks like IPv6 to me. Wagering that the rest of the Internet will be fully supporting IPv4 at the same level of utility as IPv6 in a decade looks like a high-risk gamble. Scott