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> Just look at this page: https://en.wikipedia.org/wiki/IPv6_address https://en.wikipedia.org/wiki/IPv6_address > By contrast, I can't link you to the "Wikiped

by bhauer 11y ago

> Just look at this page: https://en.wikipedia.org/wiki/IPv6_address https://en.wikipedia.org/wiki/IPv6_address > By contrast, I can't link you to the "Wikipedia page on IPv4 addresses", because it doesn't rate its own page. It just gets rolled into a single section on the IPv4 page in general: https://en.wikipedia.org/wiki/IPv4#Addressing https://en.wikipedia.org/wiki/IPv4#Addressing The above neatly encapsulates my problem with IPv6. I feel IPv6 would have much more widely adopted by now if people like myself—who have spent nominal time setting up small computer networks such as their home network—could more readily grok the deltas between v4 and v6. With the reality of v6 being so dramatically different, I have on about three separate occasions sat down to try to understand what I need to do in order to have v6 on my home network and each time I just give up after a few hours of reading. It's just so much more complicated for the amateur network operators out there. Additionally, it instills fear that if I turn on v6, I will inevitably have my home network in some tragically vulnerable state.

zAy0LfpBZLC8mAC 11y ago
> With the reality of v6 being so dramatically different, I have on about three separate occasions sat down to try to understand what I need to do in order to have v6 on my home network and each time I just give up after a few hours of reading. I don't mean to offend you, but I think that that suggests that you don't understand IPv4 either. IPv6 isn't really all that different from IPv4--with one major exception: All of the workarounds for the shortcomings of IPv4 that dominate local networks nowadays are not needed anymore, actually making networks so much simpler again. Now, many people who have learned IP networking in such environments in the last ten years or so (and I suspect you are one of those) seem to think that those workarounds are what defines IPv4 and then are confused by IPv6's lack of those workarounds, thinking that those are missing features. Maybe you think that your "internal network" is in some way fundamentally different from "the internet" and that a router is a device that connects those two to give your local network "access to the internet"? That is a common misunderstanding caused by NAT. The internet without NAT, be it IPv4 or IPv6, doesn't know any distinction between "internal" or "external" networks. It is all one network, the internet. Your LAN is not somehow "connected to the internet", it is itself part of the internet. Your home router (without NAT) is no different in function than any other router on the internet: It is connected to more than one transmission medium and thus allows devices on one medium to reach devices connected to another medium, possibly transitively through yet another (series of) routers. And it's completely symmetrical in that regard: It allows devices on your LAN to send packets to devices outside your LAN (say one of Google's webservers), but equally allows devices outside your LAN to send packets to devices on your LAN (say a webserver on your laptop). So, the most important thing you may have to completely unlearn is the idea of "private addresses" and "NAT" and "port forwarding". You don't get one address from your provider, you get a huge subnet with quadrillions of addresses that you can use to assign addresses to your devices, similar to the early days of IPv4. Your laptop gets an IPv6 address that is no different in function than the IPv6 address of Google's webserver. Other than that, details and terms differ, but the general concepts of IPv6 aren't all that different from IPv4. ARP is now NDP, DHCP is now SLAAC (or maybe still DHCPv6 if you like), ... Now, if you think that it seems problematic to have "public addresses" on your "private network": It's not, that's purely psychology. Yes, a stateful packetfilter at boundaries to other, non-trustworthy, networks might still be a good idea, just as with IPv4, whether you were using NAT or not. If anything, having one global address space makes things much less complicated, and thus more difficult to screw things up. Once you get the hang of it, you will love it and start wondering why you ever considered NAT a reasonable idea. Ever had the problem that you had multiple machines behind a NAT offering the same service that you needed to access from the outside, so you had to put one of them on a different port on "the public address"? Ever tried to access a port-forwarded service from the network behind the NAT and had it either fail because of lack of hairpin NAT, or it was slow because of the bottleneck that was the hairpin NAT? All those problems simply vanish, never to return.
- teddyh 11y ago
  Your comment gave me yet another reason to feel lucky to have learned about the Internet in the early 90’s, just before the boom. I agree with your comment enormously, and I regret that I have only one upvote to give.
- bhauer 11y ago
  Thanks for taking the time to write a very thoughtful reply. You've given me some motivation to take another look into it!

by bhauer 11y ago

zAy0LfpBZLC8mAC 11y ago

> With the reality of v6 being so dramatically different, I have on about three separate occasions sat down to try to understand what I need to do in order to have v6 on my home network and each time I just give up after a few hours of reading. I don't mean to offend you, but I think that that suggests that you don't understand IPv4 either. IPv6 isn't really all that different from IPv4--with one major exception: All of the workarounds for the shortcomings of IPv4 that dominate local networks nowadays are not needed anymore, actually making networks so much simpler again. Now, many people who have learned IP networking in such environments in the last ten years or so (and I suspect you are one of those) seem to think that those workarounds are what defines IPv4 and then are confused by IPv6's lack of those workarounds, thinking that those are missing features. Maybe you think that your "internal network" is in some way fundamentally different from "the internet" and that a router is a device that connects those two to give your local network "access to the internet"? That is a common misunderstanding caused by NAT. The internet without NAT, be it IPv4 or IPv6, doesn't know any distinction between "internal" or "external" networks. It is all one network, the internet. Your LAN is not somehow "connected to the internet", it is itself part of the internet. Your home router (without NAT) is no different in function than any other router on the internet: It is connected to more than one transmission medium and thus allows devices on one medium to reach devices connected to another medium, possibly transitively through yet another (series of) routers. And it's completely symmetrical in that regard: It allows devices on your LAN to send packets to devices outside your LAN (say one of Google's webservers), but equally allows devices outside your LAN to send packets to devices on your LAN (say a webserver on your laptop). So, the most important thing you may have to completely unlearn is the idea of "private addresses" and "NAT" and "port forwarding". You don't get one address from your provider, you get a huge subnet with quadrillions of addresses that you can use to assign addresses to your devices, similar to the early days of IPv4. Your laptop gets an IPv6 address that is no different in function than the IPv6 address of Google's webserver. Other than that, details and terms differ, but the general concepts of IPv6 aren't all that different from IPv4. ARP is now NDP, DHCP is now SLAAC (or maybe still DHCPv6 if you like), ... Now, if you think that it seems problematic to have "public addresses" on your "private network": It's not, that's purely psychology. Yes, a stateful packetfilter at boundaries to other, non-trustworthy, networks might still be a good idea, just as with IPv4, whether you were using NAT or not. If anything, having one global address space makes things much less complicated, and thus more difficult to screw things up. Once you get the hang of it, you will love it and start wondering why you ever considered NAT a reasonable idea. Ever had the problem that you had multiple machines behind a NAT offering the same service that you needed to access from the outside, so you had to put one of them on a different port on "the public address"? Ever tried to access a port-forwarded service from the network behind the NAT and had it either fail because of lack of hairpin NAT, or it was slow because of the bottleneck that was the hairpin NAT? All those problems simply vanish, never to return.

teddyh 11y ago
Your comment gave me yet another reason to feel lucky to have learned about the Internet in the early 90’s, just before the boom. I agree with your comment enormously, and I regret that I have only one upvote to give.
bhauer 11y ago
Thanks for taking the time to write a very thoughtful reply. You've given me some motivation to take another look into it!