6 ms·

The real problem with IPv6 is that it focuses too much on the technical issues and mostly ignores the human issues. This is why it hasn't gained significant tra

by CrLf 16y ago

The real problem with IPv6 is that it focuses too much on the technical issues and mostly ignores the human issues. This is why it hasn't gained significant traction and, IMHO, won't even when the IANA runs out of unallocated IPv4 blocks. There are a few main issues with IPv4: 1. Everybody wants to have a public IP address, and that is making the available IP addresses run out really fast; 2. There are huge chunks of allocated addresses that are in fact unused. And there are also a number of public addressable /8's being used for internal networks for no good reason; 3. Splitting up wasted /8's in (geographically disperse) small chunks isn't feasible because routing tables would get huge. No. 1 is easy to solve: not everybody needs a public IP address, no matter what people say. Mobile phones can survive just fine with private addressing behind a NAT. Public addresses for mobile users could be handed out on a case-by-case basis, for an additional fee. No. 2 will come into play once we run out of address space. Scarcity will trigger a market for IPv4 addresses, and as any scarce resource, its use will be rationalized and made more efficient. No. 3 is the most tricky. But that's where IPv6 really appears as the problem solver. Internet backbones will have a different structure than the IPv4 addressing implies, and that structure will be made with IPv6. IPv4 will be tunneled over IPv6 networks with its own structure. In fact, this has been done for a long while inside the ISP's networks using MPLS (IP packets enter the ISP network and are then routed using MPLS until they exit into another ISP/carrier's network). Those multiple MPLS domains will become a single IPv6 domain. The structure of the Internet will change when IPv4 addresses become scarce, that's for sure, but I seriously doubt IPv6 will gain acceptance at the network endpoints. There is just too much legacy for that to happen in the next 30 years at least. I belive in scarcity dynamics, so I'm not too worried. Also I also belive NAT to be a good solution for private networks and don't agree with the view that NAT is evil.

BerislavLopac 16y ago
1. "not everybody needs a public IP address": sure, and there is no need for more than 6 computers on the entire world, ever. In my opinion, stalling the transition hurts innovation; while it's true that as the things are at present public addresses are not an imperative, new technologies like P2P, which would greatly benefit from public addresses, open a whole new realm of possibilities. 2. Again correct, assuming that there is no cheaper alternative to the "addresses market". But it exists, and is (mostly) free. Once the providers realize that it's less expensive (longterm) to switch to IPv6 than to keep buying new addresses, they'll do it, even such a solution might prolong things even more. In general, most of "solutions" to the IPv4 crisis represent a sizable effort, which will only increase as the addresses become more scarce; and the sum of it will be much larger than the effort of simply switching to v6. We'll see how it will turn out though.
- CrLf 16y ago
  Stalling the transition hurts innovation, yes, and avoiding an address market would be good too. But this is ignoring the human problem, which was my original point. From a technological standpoint it would be nice to switch, but you have to convince everyone to switch, which isn't easy because: Most OSes deployed today either don't support IPv6 or the support is problematic. Remember that most of the world still uses Windows XP and are in no hurry to change. Most applications don't support IPv6. Many of those could be easily changed but the people responsible have better things to do, especially in the enterprise space (which most people here seem to ignore, always thinking that the consumer Internet is the only thing in existence). IPv4 is elegant in its simplicity, whereas IPv6 is complex and different for the sake of being different in some cases. This means extra cost to switch internal networks, and without switching internal networks there's no pressure to port most applications. Network administrators know IPv4 well, what works and what doesn't, where the faults are. Switching to IPv6 means extensive training which adds to the cost. Given that right now people that actually have a working knowledge of IPv6 are few and far between and seem to be concentrated in ISPs, this will be hard to change. Despite the benefits of everyone having public addresses, there are also security downsides, and these outweight the benefits in most people's eyes. So, the main problem is legacy. IPv6 benefits are irrelevant when it doesn't interoperate seamlessly with IPv4. Again, IPv6 adoption is a human problem, just like convincing people to abandon IE6 is.
  - loup-vaillant 16y ago
    > Despite the benefits of everyone having public addresses, there are also security downsides, No there isn't. Not a single one. Just replace your old NAT by a clean firewall, and you're set.
    - Dylan16807 16y ago
      Letting people see each individual device, even firewalled, is a security downside.
      - loup-vaillant 16y ago
elblanco 16y ago
1. I've just run into a couple of cases on certain types of public wi-fi network where having a public IP on my phone would have been very useful in just the last couple of days.
jamii 16y ago
> don't agree with the view that NAT is evil NAT is a nightmare for p2p applications. For algorithms that send short messages to many different peers the overhead of using STUN for every connection is enormous. See eg http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.81.2014&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.81....
- tptacek 16y ago
  P2P is a nightmare because every application is expected to provide its own connection fabric. In a content-addressed overlay network --- and there are many huge deployed examples of these deployed --- you wouldn't need to do the STUN chicken dance every time you wanted to add a peer. If this all sounds hand-wavy, well, it's already the mechanism used by the exchanges and ECNs to route stock information, and it's already a mechanism used to build CDNs. It's a considerably more straightforward evolutionary path for the Internet than forklifting out every IPv4-aware device or software package.
  - drdaeman 16y ago
    Not every P2P revolves around "content". The most well-known example would be Skype and SIP.
    - tptacek 16y ago
      Content-addressed networking doesn't imply that content is being transmitted in discrete units; it implies (what Tibco would call) subject-based addressing, and the notion of publish/subscribe. It works just fine for unicast, and even in strictly unicast situations, there are plenty of cases (conference calls, for instance) where "subscribe" turns out to be useful.
  - jamii 16y ago
    > P2P is a nightmare because every application is expected to provide its own connection fabric Well someone has to write the connection fabric, even in a content-addressed overlay. Writing a DHT that performs NAT traversal is just as difficult as for any other P2P application. See http://www.slideshare.net/vschiavoni/dht-and-nat http://www.slideshare.net/vschiavoni/dht-and-nat for some examples. CDNs have it easy because they control the network the servers are on. Writing p2p applications for the internet at large is much harder than it should be because of NAT.
ay 16y ago
Nice analysis. And locator-ID split idea in (3) is fun. However, (3) is tricky in itself - you still need the routing info to come from somewhere. And, would not matter too much whether it is IPv6 or another layer of IPv4 that are used as locators - or did I miss something in the argument ? Peering for the IPv6 should be roughly the same as now for IPv4. The scarsity dynamics and the cost of v4 vs. v6 is something I totally agree with. And with the fact that NATs are not evil per se. They're a tool just like IPv* is.
- loup-vaillant 16y ago
  > NATs are not evil per se. They're a tool just like IPv is* "Nukes are not evil per se. They're a tool just like knives are." Please avoid this kind of sentence. They're void of content, and therefore can't be contradicted, but at the same time they convey wrong ideas. Here for instance, I can't think of any direct usage of nukes that isn't evil. Because nuke explosions automatically kill people and ruin the environment. Likewise, I can't think of any usage of NATs on behalf of other people which isn't evil (though much less so). Because, you automatically end up closing all receiving ports, and they can't re-open them.
  - ay 16y ago
    "They're void of content" - no, they are just a restatement that any technology is only as evil as its use. Think P2P. One can argue it is evil because its predominant use is to distribute pirated content. But it is not. Similarly, nukes were seriously considered for plugging the oil leak - to name one recent example. If you can't think of any usage of NAT that is not harmful - it does not mean there isn't one. To start, what you mention - the stateful nature of the NATs (one of the reasons why people fight so hard to have them) - is a useful security property and is very frequently sought after by the people who want to put the NATs in IPv6. Check my vid on xtranormal that I mentioned in another message. What is harmful in NATs is that they destroy the end-to-end referrals (and when they remap the numeric ports to different ones, too). Another example of NATs that is useful and is widely used is the load balancer. It is exactly NAT, but put inside-out. Sometimes even doing SSL decapsulation. And you can use round-robin destination NAT as a poor man's loadbalancer technique (how useful it is today, is another story). To summarize: NATs are like recreational drugs. Pleasant in small dozes, lethal when uncontrolled. And people can not control themselves in using them.

by CrLf 16y ago

BerislavLopac 16y ago

1. "not everybody needs a public IP address": sure, and there is no need for more than 6 computers on the entire world, ever. In my opinion, stalling the transition hurts innovation; while it's true that as the things are at present public addresses are not an imperative, new technologies like P2P, which would greatly benefit from public addresses, open a whole new realm of possibilities. 2. Again correct, assuming that there is no cheaper alternative to the "addresses market". But it exists, and is (mostly) free. Once the providers realize that it's less expensive (longterm) to switch to IPv6 than to keep buying new addresses, they'll do it, even such a solution might prolong things even more. In general, most of "solutions" to the IPv4 crisis represent a sizable effort, which will only increase as the addresses become more scarce; and the sum of it will be much larger than the effort of simply switching to v6. We'll see how it will turn out though.

CrLf 16y ago
Stalling the transition hurts innovation, yes, and avoiding an address market would be good too. But this is ignoring the human problem, which was my original point. From a technological standpoint it would be nice to switch, but you have to convince everyone to switch, which isn't easy because: Most OSes deployed today either don't support IPv6 or the support is problematic. Remember that most of the world still uses Windows XP and are in no hurry to change. Most applications don't support IPv6. Many of those could be easily changed but the people responsible have better things to do, especially in the enterprise space (which most people here seem to ignore, always thinking that the consumer Internet is the only thing in existence). IPv4 is elegant in its simplicity, whereas IPv6 is complex and different for the sake of being different in some cases. This means extra cost to switch internal networks, and without switching internal networks there's no pressure to port most applications. Network administrators know IPv4 well, what works and what doesn't, where the faults are. Switching to IPv6 means extensive training which adds to the cost. Given that right now people that actually have a working knowledge of IPv6 are few and far between and seem to be concentrated in ISPs, this will be hard to change. Despite the benefits of everyone having public addresses, there are also security downsides, and these outweight the benefits in most people's eyes. So, the main problem is legacy. IPv6 benefits are irrelevant when it doesn't interoperate seamlessly with IPv4. Again, IPv6 adoption is a human problem, just like convincing people to abandon IE6 is.
- loup-vaillant 16y ago
  > Despite the benefits of everyone having public addresses, there are also security downsides, No there isn't. Not a single one. Just replace your old NAT by a clean firewall, and you're set.
  - Dylan16807 16y ago
    Letting people see each individual device, even firewalled, is a security downside.
    - loup-vaillant 16y ago

elblanco 16y ago

1. I've just run into a couple of cases on certain types of public wi-fi network where having a public IP on my phone would have been very useful in just the last couple of days.

jamii 16y ago

> don't agree with the view that NAT is evil NAT is a nightmare for p2p applications. For algorithms that send short messages to many different peers the overhead of using STUN for every connection is enormous. See eg http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.81.2014&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.81....

tptacek 16y ago
P2P is a nightmare because every application is expected to provide its own connection fabric. In a content-addressed overlay network --- and there are many huge deployed examples of these deployed --- you wouldn't need to do the STUN chicken dance every time you wanted to add a peer. If this all sounds hand-wavy, well, it's already the mechanism used by the exchanges and ECNs to route stock information, and it's already a mechanism used to build CDNs. It's a considerably more straightforward evolutionary path for the Internet than forklifting out every IPv4-aware device or software package.
- drdaeman 16y ago
  Not every P2P revolves around "content". The most well-known example would be Skype and SIP.
  - tptacek 16y ago
    Content-addressed networking doesn't imply that content is being transmitted in discrete units; it implies (what Tibco would call) subject-based addressing, and the notion of publish/subscribe. It works just fine for unicast, and even in strictly unicast situations, there are plenty of cases (conference calls, for instance) where "subscribe" turns out to be useful.
- jamii 16y ago
  > P2P is a nightmare because every application is expected to provide its own connection fabric Well someone has to write the connection fabric, even in a content-addressed overlay. Writing a DHT that performs NAT traversal is just as difficult as for any other P2P application. See http://www.slideshare.net/vschiavoni/dht-and-nat http://www.slideshare.net/vschiavoni/dht-and-nat for some examples. CDNs have it easy because they control the network the servers are on. Writing p2p applications for the internet at large is much harder than it should be because of NAT.

ay 16y ago

Nice analysis. And locator-ID split idea in (3) is fun. However, (3) is tricky in itself - you still need the routing info to come from somewhere. And, would not matter too much whether it is IPv6 or another layer of IPv4 that are used as locators - or did I miss something in the argument ? Peering for the IPv6 should be roughly the same as now for IPv4. The scarsity dynamics and the cost of v4 vs. v6 is something I totally agree with. And with the fact that NATs are not evil per se. They're a tool just like IPv* is.

loup-vaillant 16y ago
> NATs are not evil per se. They're a tool just like IPv is* "Nukes are not evil per se. They're a tool just like knives are." Please avoid this kind of sentence. They're void of content, and therefore can't be contradicted, but at the same time they convey wrong ideas. Here for instance, I can't think of any direct usage of nukes that isn't evil. Because nuke explosions automatically kill people and ruin the environment. Likewise, I can't think of any usage of NATs on behalf of other people which isn't evil (though much less so). Because, you automatically end up closing all receiving ports, and they can't re-open them.
- ay 16y ago
  "They're void of content" - no, they are just a restatement that any technology is only as evil as its use. Think P2P. One can argue it is evil because its predominant use is to distribute pirated content. But it is not. Similarly, nukes were seriously considered for plugging the oil leak - to name one recent example. If you can't think of any usage of NAT that is not harmful - it does not mean there isn't one. To start, what you mention - the stateful nature of the NATs (one of the reasons why people fight so hard to have them) - is a useful security property and is very frequently sought after by the people who want to put the NATs in IPv6. Check my vid on xtranormal that I mentioned in another message. What is harmful in NATs is that they destroy the end-to-end referrals (and when they remap the numeric ports to different ones, too). Another example of NATs that is useful and is widely used is the load balancer. It is exactly NAT, but put inside-out. Sometimes even doing SSL decapsulation. And you can use round-robin destination NAT as a poor man's loadbalancer technique (how useful it is today, is another story). To summarize: NATs are like recreational drugs. Pleasant in small dozes, lethal when uncontrolled. And people can not control themselves in using them.