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> The nice thing about NAT [...] I really do think IPv6 missed a trick by not offering that IPv6 supports NAT [0], and nearly all routers make it easy to enabl

> The nice thing about NAT [...] I really do think IPv6 missed a trick by not offering that IPv6 supports NAT [0], and nearly all routers make it easy to enable. The primary differences compared to IPv4 is that no-NAT is the default, and that it's more heavily discouraged, but it still works just as well as it does with IPv4. [0]: In the same way that IPv4 "supports" NAT, meaning that the protocol doesn't officially support it, but it's still possible to implement.

wongarsu 6mo ago
But would we have said the same in 1996 or 2000? Part of the adoption curve seems to be that it took years to abandon some of the bad ideas around IPv6 and readopt some of the better ones from IPv4. And a good chunk of the complexity of IPv6 is that some of the early ideas are very persistent, both in some deployed systems and in people's minds
- gucci-on-fleek 6mo ago
  > But would we have said the same in we 1996 or 2000? IPv6 the protocol supported NAT just as well back then as it does now, but the software probably didn't. Which goes back to my point [0] [1] that IPv6 is a great protocol with bad tooling and documentation. > Part of the adoption curve seems to be that it took years to abandon some of the bad ideas around IPv6 and readopt some of the better ones from IPv4. The only abandoned IPv6 concept that I'm personally aware of is A6 records [2], but I'm pretty young, so I'm sure that there are others that I'm just not aware of. My impression from reading the RFCs and Wikipedia is that IPv6 hasn't changed very much, but that doesn't really mean anything, since I wouldn't expect for current sources to talk about concepts abandoned 20+ years ago. [0]: https://news.ycombinator.com/item?id=47814070 https://news.ycombinator.com/item?id=47814070 [1]: https://news.ycombinator.com/item?id=44773999 https://news.ycombinator.com/item?id=44773999 [2]: https://datatracker.ietf.org/doc/html/rfc6563 https://datatracker.ietf.org/doc/html/rfc6563
  - izacus 6mo ago
    Just because it technically supported something in some RFC it doesn't mean you could get affordable and capable equipment supporting it.
ButlerianJihad 6mo ago
> IPv6 supports NAT You say that, but in practice it does not. My consumer router, and every router I have configured, implicitly supports IPv4 NAT out of the box. But it will never NAT an IPv6 network. If I enable IPv6 then it operates by IPv6 rules, which means each device gets a Network ID and each Network ID gets routed directly and transparently. The router has no NAT table and no NAT settings for this protocol. So if NAT is “supported” whatever that means, it simply isn’t possible for most end-users.
- gucci-on-fleek 6mo ago
  Consumer routers don't support lots of useful stuff though, so them not supporting NAT66 isn't very surprising. Enthusiasts are likely to use OpenWRT or nftables, both of which support NAT66 [0], and quickly Googling some random enterprise routers shows that they all support NAT66 too [1] [2] [3]. This isn't enabled by default because it's usually a bad idea, but it's certainly possible if you really want. (It's discouraged because NAT in general is a bad idea, but it's no worse with IPv6 than with IPv4; the only difference being that IPv4 effectively requires NAT.) [0]: https://openwrt.org/docs/guide-user/network/ipv6/ipv6.nat6 https://openwrt.org/docs/guide-user/network/ipv6/ipv6.nat6 [1]: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nat/configuration/xe-16-11/nat-xe-16-11-book/iadnat-asr1k-nptv6.html https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nat... [2]: https://www.animmouse.com/p/how-to-nat-ipv6-in-mikrotik/ https://www.animmouse.com/p/how-to-nat-ipv6-in-mikrotik/ [3]: https://www.juniper.net/documentation/us/en/software/junos/interfaces-next-gen-services/topics/task/usf-basic-nat44-configuring.html https://www.juniper.net/documentation/us/en/software/junos/i...
- shibapuppie 6mo ago
  IPv6 DOES support NAT. If you've got a car that can't go 100, that doesn't mean nobody can, or that it doesn't exist. I don't care if you can't do it, it IS supported in the spec.
  - hnlmorg 6mo ago
    That’s an interesting analogy because there’s several ways you could easily dismiss it. For example: if roads aren’t built to support cars travelling at 100 miles per hour then it doesn’t matter how much you argue that cars are can do 100MPH, because you’re still not going to be travelling at 100MPH. Or But if the only cars that can travel at 100 MPH are Bugatti Veyrons then it’s safe to say that 100MPH cars isn’t something available to even the average consumer of high end sports cars. Or Sure, some cars can travel at 100 MPH, but they’re so unstable at those speeds that it’s not even safe to attempted it. …You get the idea.

wongarsu 6mo ago

But would we have said the same in 1996 or 2000? Part of the adoption curve seems to be that it took years to abandon some of the bad ideas around IPv6 and readopt some of the better ones from IPv4. And a good chunk of the complexity of IPv6 is that some of the early ideas are very persistent, both in some deployed systems and in people's minds

gucci-on-fleek 6mo ago
> But would we have said the same in we 1996 or 2000? IPv6 the protocol supported NAT just as well back then as it does now, but the software probably didn't. Which goes back to my point [0] [1] that IPv6 is a great protocol with bad tooling and documentation. > Part of the adoption curve seems to be that it took years to abandon some of the bad ideas around IPv6 and readopt some of the better ones from IPv4. The only abandoned IPv6 concept that I'm personally aware of is A6 records [2], but I'm pretty young, so I'm sure that there are others that I'm just not aware of. My impression from reading the RFCs and Wikipedia is that IPv6 hasn't changed very much, but that doesn't really mean anything, since I wouldn't expect for current sources to talk about concepts abandoned 20+ years ago. [0]: https://news.ycombinator.com/item?id=47814070 https://news.ycombinator.com/item?id=47814070 [1]: https://news.ycombinator.com/item?id=44773999 https://news.ycombinator.com/item?id=44773999 [2]: https://datatracker.ietf.org/doc/html/rfc6563 https://datatracker.ietf.org/doc/html/rfc6563
- izacus 6mo ago
  Just because it technically supported something in some RFC it doesn't mean you could get affordable and capable equipment supporting it.

ButlerianJihad 6mo ago

> IPv6 supports NAT You say that, but in practice it does not. My consumer router, and every router I have configured, implicitly supports IPv4 NAT out of the box. But it will never NAT an IPv6 network. If I enable IPv6 then it operates by IPv6 rules, which means each device gets a Network ID and each Network ID gets routed directly and transparently. The router has no NAT table and no NAT settings for this protocol. So if NAT is “supported” whatever that means, it simply isn’t possible for most end-users.

gucci-on-fleek 6mo ago
Consumer routers don't support lots of useful stuff though, so them not supporting NAT66 isn't very surprising. Enthusiasts are likely to use OpenWRT or nftables, both of which support NAT66 [0], and quickly Googling some random enterprise routers shows that they all support NAT66 too [1] [2] [3]. This isn't enabled by default because it's usually a bad idea, but it's certainly possible if you really want. (It's discouraged because NAT in general is a bad idea, but it's no worse with IPv6 than with IPv4; the only difference being that IPv4 effectively requires NAT.) [0]: https://openwrt.org/docs/guide-user/network/ipv6/ipv6.nat6 https://openwrt.org/docs/guide-user/network/ipv6/ipv6.nat6 [1]: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nat/configuration/xe-16-11/nat-xe-16-11-book/iadnat-asr1k-nptv6.html https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nat... [2]: https://www.animmouse.com/p/how-to-nat-ipv6-in-mikrotik/ https://www.animmouse.com/p/how-to-nat-ipv6-in-mikrotik/ [3]: https://www.juniper.net/documentation/us/en/software/junos/interfaces-next-gen-services/topics/task/usf-basic-nat44-configuring.html https://www.juniper.net/documentation/us/en/software/junos/i...
shibapuppie 6mo ago
IPv6 DOES support NAT. If you've got a car that can't go 100, that doesn't mean nobody can, or that it doesn't exist. I don't care if you can't do it, it IS supported in the spec.
- hnlmorg 6mo ago
  That’s an interesting analogy because there’s several ways you could easily dismiss it. For example: if roads aren’t built to support cars travelling at 100 miles per hour then it doesn’t matter how much you argue that cars are can do 100MPH, because you’re still not going to be travelling at 100MPH. Or But if the only cars that can travel at 100 MPH are Bugatti Veyrons then it’s safe to say that 100MPH cars isn’t something available to even the average consumer of high end sports cars. Or Sure, some cars can travel at 100 MPH, but they’re so unstable at those speeds that it’s not even safe to attempted it. …You get the idea.