> Why run your K8S cluster on IPv6 when IPv4 with 10.0.0.0/8 works perfectly with less hassle? You can always support IPv6 at the perimeter for ingress/egress.
How is it "less hassle"? You've got to use a second, fiddlier protocol and you've got to worry about collisions and translations. Why not just use normal IPv6 and normal addresses for your whole network, how is that more hassle?
> You can always support IPv6 at the perimeter for ingress/egress. If your cluster is so big it can’t fit in 10.0.0.0/8, maybe the right answer is multiple smaller clusters-your service mesh (e.g. istio) can route inter-cluster traffic just based on names, not IPs.
You can work around the problems, sure. But why not just avoid them in the first place?
> How is it "less hassle"? You've got to use a second, fiddlier protocol and you've got to worry about collisions and translations.
Because, while less common than it used to be, software that has weird bugs with IPv6 is still a thing-especially if we are talking about internally developed software as opposed to just open source and major proprietary packages. And as long as IPv6 remains the minority in data centre environments, that’s likely to remain true - it is easy for bugs to linger (or even new ones to be introduced) when they are only triggered by a less popular configuration
True, but already the newest software has good IPv6 support, and that suggests a tipping point should be coming where as soon as the majority is on IPv6 it becomes in everyone's interest to get off of IPv4.