alt Hacker News> I don't get your point. IPv6 is at "boring, just works". The majority of the worlds devices run on it dual-stack and it handles a considerable amount of traffic.
Most of the world runs on IPv4. If we shut down IPv6 on the core routers tomorrow, pretty much nobody is going to blink an eye. And now I believe that we should do it and start again.
The 50% stat is really mostly mobile phones on cellular networks, which remain the _only_ major success story for IPv6. Mostly because there's not enough private or even squattable IPv4 space available for many large mobile phone operators.
> IPv6 is very much alive. And it's so boring and working so well, that you don't even notice it.
Sigh. No, it's not. In a thread a couple of weeks ago, I gave several examples:
1. You're a SOHO-type business. How can you do multiple WAN uplinks with IPv6 without NAT?
2. How do you prevent your printer on IPv6 from breaking when your Internet connection goes down?
For context: I deployed IPv6 in my networks in 2006. I have war stories.
Replies
> The 50% stat is really mostly mobile phones on cellular networks, which remain the _only_ major success story for IPv6.
The largest ISPs in the US are Comcast, AT&T, Charter, Verizon, T-Mobile, Starlink, and Google Fiber. They all support IPv6. The only top-10 US provide that didn't support it is Frontier Communications, who is rolling it out.
In other words, the biggest companies who actually do this for a living all demonstrate that you're wrong.
As to your questions, read up on IPv6 ULA which solves all of them. None of the hosts on my LAN depend on having an outbound connection.
> For context: I deployed IPv6 in my networks in 2006. I have war stories.
Early IPv6 was a mess. It took a surprising amount of time for IPv6 to become mature and usable.
> How can you do multiple WAN uplinks with IPv6 without NAT?
Advertise the addresses offered by the primary uplink, then retire those addresses [0] and advertise the secondary when the primary fails. Or are you talking about load balancing, which is its own thing? Either way, this situation is inherently not boring, so the way you solve it is going to be quite a bit more complex -regardless of IP protocol version- than the very boring single-upstream situation.
> How do you prevent your printer on IPv6 from breaking when your Internet connection goes down?
I'll flip this around on you:
How do you prevent your printer from "breaking" when its ISP-provided DHCP lease on its globally-routable IPv4 address expires? How about when the ISP refuses to renew the lease on the printer's current globally-routable IPv4 address and forces it to get a new one?
Obviously, you use the ISP-assigned globally-routable IPv4 address and also assign an RFC 1918 address to the printer.
How to solve this with IPv6? Use ULAs! They're the equivalent of 1918 space in the IPv6 world. Just like in IPv4, IPv6 globally-routable addresses are for global communication and can be used for LAN-local communication. And -just like 1918 addresses- ULAs are for LAN-local communication. Just like with IPv4, if you can't control the addresses that you get from your upstream provider, and/or if your router is set up to retire your upstream provider's delegated address space when your upstream link goes down, then you use ULAs. [1]
I know that OpenWRT has a setting in LuCi to enable advertisement of a ULA prefix, and fifteen seconds of searching revealed that at least some Linksys combination router/APs seem to just generate and advertise a ULA prefix by default. [2]
So, if you're not configuring your LAN this way and upstream provider renumbering is getting in your way, then you really should bother to.
[0] ...by advertising their valid lifetime as zero seconds...
[1] ...or if you happen to like to be able to assign fixed IP addresses to certain pieces of hardware...
[2] <https://support.linksys.com/kb/article/3744-en/>