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Vint Cerf Answers Your Questions About IPv6 and More 150

Last week, you asked questions of "father of the Internet" Vint Cerf; read on below for Cerf's thoughts on the present and future of IPv6, standards and nomenclature, the origin of his beard, and more. Thanks, Vint!
What can we do to get ISPs to switch on IPv6?
by jandrese

One of the biggest hurdles to IPv6 adoption today is that the average home user simply cannot get an IPv6 address from their ISP. Tunnels are hacker toys, and completely impractical/impossible for people who are using their ISP's "home router". What do you think we can do to convince ISPs to start rolling out IPv6 [i]before[/i] there is a crisis? Everybody agrees that the transition will go smoother if we take it slow and easy, but nobody is willing to make the first step, and IPv4 addresses aren't still being inexorably depleted the world over.

VC: I have been asking myself (and others) this question for some years now! When you try to explain that they can't really expand the Internet effectively relying solely on cascading NAT boxes they kind of glaze over. Sadly, now that we really are in the IPv4 end-game, there is not much choice but to deploy NATs to try to make dual-stack work as a transition plan. If ISPs had started implementing IPv6 5 years ago we would not have this problem. I think only pressure from consumers, businesses and governments to demand IPv6 implementation will help. Even then, I can imagine the bean counters insisting that there be incremental revenue for implementing IPv6 despite the simple fact that the only serious path to supporting smart devices (including smart grid, mobiles with IP addresses, etc) is through implementation of IPv6. We are also going to have to find some incentives for users to upgrade their home routers to handle both IPv4 and IPv6. Maybe a trade-in policy???

IPV6, and a related question
by gr8_phk

With IPv6 we could all have fixed IP addresses (or blocks of them) at home. Is this likely to happen? What do you see as the pros and cons from the ISP point of view for doing this? I think the reasons I want it are the reasons they don't, but I'd like to know how someone with your perspective sees it.

VC: We could actually have a fairly large group of IPv6 addresses at each termination point. An advantage is that one could then run servers but some ISPs might find that problematic because of the potential uplink traffic. I ended up paying for "business" class service to assure fixed IP addresses for that reason. I did not have servers of video or imagery in mind, but, rather, controllers and sensors (and ability to print remotely, for instance).

Hardware accelerated IPv6
by vlm

Hardware accelerated ipv4 routing/switching was out there, I dunno, at least a decade ago, or more. Your expectations on the rollout of hardware accelerated ipv6 switching?

VC: It probably won't happen until there is clear evidence of an IPv6 tipping point. Of course, it makes every bit of good sense and the IPv6 format is better geared to hardware assist than IPv4.

Why the colon in IPv6?
by jandrese

The biggest thing I hate about IPv6 is that the standard format uses colon as the digit separator. On most keyboards, that is a fairly awkward character to type, especially in rapid fire between groups of hex digits. Also, it causes problems for the many many programs that specify ports after IP addresses with a colon (like URIs!). IPv4's use of the period instead is much nicer. If you didn't want to reuse the period (so programs can distinguish between the two types of addresses more easily), why not use dash instead? It's just as visually appealing and doesn't require you to hit shift to type it. It would have saved a whole lot of ugly brackets around IP addresses.

Any aesthetic qualities of the colon are lost when you have to do this:
http:/// [http] [1005:3321:5a52:4fca::1]:8080/
instead of: http://1005-3321-5a52-4fca--1:8080/ [1005-3321-5a52-4fca--1]

And that second example was noticeably quicker for me to type.

Edit: And of course because this is Slashdot it made a huge mess of the first URL and forced me to mess it up slightly to be readable!

VC: The colon was needed to allow for compressed display of IPv6 addresses and to avoid confusion with a dotted representation of IPv4. It was apparently the only character thought to be unencumbered for this purpose at the time. Other slashdot readers may have additional comments on this.

Hindsight is 20/20
by eldavojohn

If there was one thing you could go back and change about TCP/IP -- something that is far too entrenched to change now -- what would it be?

VC: Well, I wish I had realized we'd need more than 32 bits of address space! At the time, I thought this was still an experiment and that, if successful, we would develop a production version. I guess IPv6 is the production version! I would also have included a lot of strong authentication mechanisms but at the time we were standardizing TCP/IP (version 4), there was no practical public key crypto capability ready in hand.

.here TLD?
by TheLink

Do you think there should be a .here TLD, reserved officially for local use in an analogous way to the way that the RFC1918 IP addresses are reserved officially for private use?

Currently many are coming up with their own ad hoc TLDs for local use. In my opinion this is suboptimal. Having a standard official TLD would allow more interesting things to "organically grow" on it.

(See also:

VC: Hard to say, honestly. I am not sure just what ".here" might actually mean unless intended to be self-referential (in other words, the server is the same as the referring party - kind of like In that case, it need only be a reserved term rather than something you register in.

Ooh! Settle An Argument For Me!
by Greyfox

Though my deep and thoughtful meditation on IP addressing, I have realized that an IP address is simply a number. We canonically break it up into 4 smaller numbers that are presumably easier to remember. However if you stack all the bits of those smaller numbers together, you get a bigger number, and that number is actually the address. Moreover, every C standard library that I have ever tried is able to resolve this bigger number to the correct address. If I ping a 10 digit number in that address range, the C standard library will figure it out. It is my position that this is a feature and not a bug.

It seems that the OS X Firefox Guys don't agree with me. Admittedly they do have an RFC on the subject, but their browser breaks a known behavior that every other TCP/IP client program on the planet exhibits, including other operating system versions of Firefox!

Would you kindly bludgeon one of us into submission? I don't really care which side of the argument you come down on, but one of us has to be able to say "Because Vint Cerf said so!"

Oh, and while I've got you, I'm sick of writing stateless http applications. May I have your permission to go back to writing plain old socket servers on other ports, providing data based on whatever query format I feel like implementing? It kind of looks like REST, I suppose, except that I don't have to load 14 layers of frameworks to get to that point.

VC: LOL! actually, most of us assumed that any way to generate the 32 number should be acceptable since the connection process doesn't actually use the text representation of the IP address. I think any value in the range 0 to 2^32-1 should be acceptable as an IP reference. As to stateless operation, I know what you mean; you have to get used to figuring out how to stash intermediate state (cookies usually)...

SMTP, DNS, U.S. Customs
by molo

It seems that it is getting more and more difficult to successfully run your own SMTP server. See, for example, this post responding to the idea that a user was going to move off gmail to their own server. Are there any prospects for meaningful SMTP reform that would lower the barrier to entry for legitimate emailers?

DNS has been often criticized as a centralized single point of failure / censorship. Have you been following the development of namecoin and P2P DNS? Are these systems viable in your estimation? How would you improve them or encourage their adoption?

The U.S. Customs department recently created headlines in seizing domains. These seizures appear to be extra-legal (not founded in law), but ICANN has gone along with them. Are those fair statements? Should ICANN's trustworthiness be suspect as a result of this process?

VC: On SMTP, the problem is spam. If SMTP relays could be authenticated in some way, perhaps running your own would work better. As of now, it is a problem to validate relays and most ISPs don't allow it. Maybe we will make some progress in this when we can strongly authenticate/validate end points in the network better. Regarding alternatives to DNS, it would be interesting to find alternatives to DNS that might be less prone to the business models that produce domaining, for example, but I have not yet seen evidence that such an outcome is likely to gain traction. I am not sure that ICANN has any ability to resist effectively the so-called seizures of domain names by the DHS/ICE. I am disturbed by the argument that this is comparable to FBI "seizures" of contraband for many reasons but I think the ability to resist this would rest on a successful court challenge to the practice, not to an ICANN policy.

Smart Grid
by kiwimate

You're currently on the Governing Board of the NIST Smart Grid Interoperability Panel. What is the state of standards development, and how big an impact does it have to move national infrastructure communications into the public IP arena so far as our ability to strengthen and expand our infrastructure? Conversely, how big are the threats in this new world?

VC: The process is moving along reasonably well although adoption of the standards that are emerging in the US will depend on endorsement by FERC and NERC. I think the standards can be very beneficial to the creation of interoperable energy management systems, edge devices, and device controllers. I am pleased that IPv6 forms a major basis for edge communication but concerned that the domestic ISPs, with some notable exceptions, have been slow to roll out support for IPv6. I imagine that an IPv6-equipped mobile could easily become a remote controller for a wide range of IPv6-labelled devices.

What would you like to see developed next?
by techmuse

I'm curious what technologies you would like to see developed next, or what you think would be most important to develop next. In other words, what do you think researchers should work on now that would be most significant? (Oh, and thank you for changing my life!)

V: My major wish right now, apart from ISP implementation of IPv6, DNSSEC and more end/end crypto and strong, 2-factor authentication, is the implementation of true broadcast IP. Satellites raining IP(v6) packets to Earth in range of millions of receivers could make widespread digital distribution of information far more efficient.

Interplanetary Internet
by immakiku TCP/IP started as a military project but has been adapted for all the Internet applications we see today. What sort of applications do you foresee/imagine for the Interplanetary Internet, aside from the stated purpose of coordinating NASA devices?

VC: The primary terrestrial applications are military tactical communications and enhanced mobile communications. I see a role for these delay and disruption tolerant protocols in public safety networking as well. All devices in the system could also serve as relays to allow for the dynamic creation of Mobile Ad hoc Networks, making more resilient emergency services communications and any number of popular user apps on mobiles.
The IP of TCP/IP

The head of UN's WIPO believes that the Internet (and obviously the stack on which it runs) should have been patented. How do you believe it would have evolved, would TCP/IP be protected by patents?

VC: This is really pretty silly. Bob Kahn and I consciously did NOT patent or control distribution of the design and protocol specifications for TCP/IP for the simple reason that we wanted no intellectual property barriers to the adoption of TCP/IP as an international standard. I see absolutely no utility in the proposition to patent TCP/IP. It would have given a reason for SNA, DECNET and other proprietary protocols to persist since their inventors/purveyors could have argued that licensing TCP/IP (had it been patented) would be of no interest to them - indeed, its use opened up interoperability among many brands of computers (and networks) leading to more competition.

Has the Internet become too centralized?
by slashsloth

That is to say, do you think that too much power & control now lies in the hands of the Internet Service Providers, thereby making it, at least in terms of control if not routing, too centralized & too easily manipulated by the powerful few. I guess this question stems from a viewpoint that it should be somehow democratic & free (as in free speech). Also do you share my pedantic belief that the public Internet should be spelt with a capital 'I'?

VC: As to the latter, yes, I strongly believe that the capital was intended to refer to the public Internet (I have written on this in the past). We accepted the notion that "internet" could use the protocols but be private and disconnected from the public Internet but that "Internet" referred to the latter. Some people disagree but I still believe it to be a useful distinction. As to centralization, it is possible that the lack of competition among Internet access providers is a bad outcome. I have always been a proponent of intra-modal competition through open access to underlying transport networks but not everyone agrees with me.

How can we bring trust back to the internet?
by Madman

One of the secrets of the internet's massive success is the lack of controls over it; if there had been strict security and processes in place it would likely not have come about. One of the downsides is that all our security measures are tacked-on, there is no built-in security to the protocols used on the internet and as a result security is a massive problem. How do we go from the wild west to having at least a reasonable level of trusted computing?

VC: Better and stronger authentication would help. 2-factor "passwords" and registration of devices. We may also need to adopt international norms for acceptable usage of the net with some kind of enforceable rules with reciprocity. Until we have some collective and cross-border ability to bring miscreants to justice, we will continue to see relatively unconstrained behaviors including harmful ones.

No more "peace and love" in software designs
by BeforeCoffee

I take it that the "route around failures" and other original design features of TCP/IP and the Internet as a whole relied upon trusting others always having good intentions and cooperating. Those designs were necessary at the time and the reason the internet exists today.

Nowadays distrust, firewalls, and coding defensively is the norm (or it should be). In that light, the internet's design seems creaky and vulnerable.

Do you have any thoughts or feelings on how software has changed and seemingly become so treacherous since you first designed TCP/IP? Would you advocate a ground-up redesign of internet transports and protocols starting with TCP/IP?

VC: I have always been a fan of trying clean-sheet designs. Sometimes you discover retrofits that don't require a re-design. In other cases (such as delay and disruption tolerance) you need serious re-implementation of new designs. It is clear that authentication, various forms of cryptographic protections and the like are needed at several layers in the architecture. Deploying something wholly new is hard, though.

Future of the Internet
by H0bb3z

Do you feel the security concerns over collected information will trump the leveraging of information in future Internet technologies? Will there be a separate "opt-in" or "opt-out" web to cater to each preference?

Context: There have been many controversies recently regarding the collection of data and the privacy of individual information. As we move forward, I've heard a mixed set of messages regarding the direction we should expect to see.

Consumerism is indeed driving innovation and everything is going mobile these days (there's an app for that I think). One example I heard recently of the benefit of the convergence of information and mobility: a consumer can point their mobile phone at a shelf of groceries, get an active "overlay" of information regarding the products and determine which best suits the customer needs. On the flip side, sensors that track customer behavior are installed at the grocery shelf and based on detected behavior (like stopping for a moment to reminisce about Coco-Puffs even though you know they are bad for you) initiates a coupon for whatever the vendor may feel would provide enough motivation to purchase their product -- in the example a $1 off coupon to the mobile phone of a shopper.

Will this become reality in the future?

I think there are benefits to be had, but also am fiercely protective of my personal information and preferences.

VC: At least in America, we have tended to readily give up privacy in exchange for convenience. Credit card information bases being a good example of that. If one can divorce identity from behavior patterns, it might be acceptable to many to benefit from system reactions to our choices and behavior if these are not correlated with identity.

Postel and Crocker
by vlm

So you went to high school with Postel and Crocker, according to Wikipedia; did you guys hang out all along or meet up decades later?

V: Crocker and I have been best friends since about 1959. Jon was in a later class and we didn't know him until we all reconvened at UCLA in the late 1960s.

A Simple Pogonological Question
by eldavojohn

What level of success does TCP/IP owe to your glorious beard?

VC: LOL!! not much! I just got tired of nicks and cuts from shaving my whole face and went with the beard!! I did shave it off once, but quickly re-grew it after being painfully reminded why I had grown it in the first place!!!
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Vint Cerf Answers Your Questions About IPv6 and More

Comments Filter:
  • by csnydermvpsoft (596111) on Tuesday October 25, 2011 @11:38AM (#37832794) Homepage

    NAT decouples the internal private network from the external network - and I'm sure any IT admin who has had to renumber their internal network would agree it's a huge PITA on IPv4. They see the ISP giving them a prefix and changing that prefix willy-nilly causing lots of fun for everyone inside.

    IPv6 provides an excellent way to address this: prefix delegation []. Your router gets a prefix assignment automatically from your ISP and advertises it to clients. If the ISP renumbers, everything is automatically reconfigured when the ISP's announcement changes. The only issue is DNS, and there are mechanisms to ease that as well (though some manual intervention is required with current tooling).

    More importantly, prefixes won't need to change very often. The only times I've ever had to renumber were when I was either changing ISPs or when I wanted a different size IP block. The former case still exists (though the mechanisms I mentioned above help with that transition), but the latter case should be virtually nonexistent, as everyone will be assigned a block of subnets large enough to service them for the foreseeable future, no matter how big they get.

    Even worse - home users, who most likely do NOT have a working DNS setup and have to type the damn things in.

    Thankfully, there are solutions for this problem as well - and they're already widespread. Look for technologies such as zeroconf to become even more common going forward (all of the printers I've purchased in the past few years - including a large corporate laser [Ricoh] and two smaller multifunctions [Brother] - include and enable it by default).

  • by CAPSLOCK2000 (27149) on Tuesday October 25, 2011 @11:46AM (#37832878) Homepage

    Even worse - home users, who most likely do NOT have a working DNS setup and have to type the damn things in. And just when my parents have gotten used to typing the long string of nonsense garbage to hit the printer, the ISP changes their prefix and they have to learn a new set of IPs.

    Multicast DNS is gaining traction. Multicast is a requirement for IPv6 anyway so it has a reasonable chance of working.
    In my experience most parent-class-beings are unable to deal with raw IPv4 either.

  • by vlm (69642) on Tuesday October 25, 2011 @11:51AM (#37832942)

    If you don't want global addrs, don't use them. Use link local addrs inside and have everyone talk thru a proxy. Its Just Not A Big Deal.

    If you don't want world wide access to your local printer, put it on a vlan thats not running radvd handing out global addrs...

    Basically your "private" web browsing clients will get inet access via "squid" instead of "iptables nat". The industry has been moving toward "everything over port 80" anyway for a decade or two now.

    Static DNS is dead/dying/soon no longer usable. Will that be a change? Yeah. So start changing now, so you're not trying to do dyndns and ipv6 at the same time. Dynamic for global and simple multicast DNS for internal. Yes multicast DNS is an unholy pain between VLANs, but it can be (carefully) done.

    We "need" a way to actively repeatedly quickly renumber DNS because our ISP "needs" to shuffle their precious resource of tiny little /20's around to different POPs because there is an intense shortage of ipv4 space. So we can't roll out ipv6 until it supports the intense address churn required by ipv4. Err, wait a second, we don't need that administrative load of address renumbering with ipv6, thats kinda the whole point. Standard /. car analogy is we can't roll out automobiles because we are having a production problem at the horse harness factory and the customers have always needed horse harnesses with our coaches so lets not roll out "the car" until we have a guaranteed scalable horse harness factory, otherwise what would our customers use to harness their new cars?

    At some point, randomly renumbering people in ipv6 is going to be considered red in the face screaming into the phone "contract breaking time" not just business as usual another day at the office ho hum. Maybe you should expect a faxed/emailed maint notification for ipv6 renumbering?

You don't have to know how the computer works, just how to work the computer.