[EKS] [Feature]: Windows IPv6 Support

[BenB196]

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Tell us about your request

IPv6 support was added in early 2022. In the official announcement, it was noted that Windows was not supported:

IPv6 is not supported on Windows nodes at the moment. We are currently working on adding IPv6 support to Windows.

This is still true today, per the docs

You can't use IP prefixes with Windows nodes. This is a requirement for using IPv6, so you can't use IPv6 with Windows nodes either.

I wasn't able to find an existing issue in this repo to actually track/gauge interest in this feature, so I'm opening this one. (If I missed an issue that already exists, or if its in a different repo, please feel free to close this one out as a duplicate).

Which service(s) is this request for?
EKS

Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?
What outcome are you trying to achieve, ultimately, and why is it hard/impossible to do right now? What is the impact of not having this problem solved? The more details you can provide, the better we'll be able to understand and solve the problem.

Are you currently working around this issue?

I'm currently just not running Windows nodes on EKS clusters.

Additional context

Being able to run Windows nodes in EKS IPv6 clusters would greatly allow for wider adoption of EKS within organizations that are heavily Windows based, while not needing to burn IPv4 addresses/subnets for large scale deployments.

[gillg]

Per some fantastic explainations about IPv6 on windows containers here microsoft/Windows-Containers#386 (comment) I suspect there is some missing things in the AWS CNI to support that.

As I understand by playing with the HCN API through the CNI it could be possible to handle the IPv6 correctly...

[goyalpurvi]

Hi @BenB196 While Kubernetes on Windows doesn't support IPv6 today (only dual stack), your issue with IP exhaustion technically may not be solved through dual stack support on EKS Windows.
However, we launched support for prefix delegation on Windows in June 2023 to help expand the number of pods you can run within a node.

https://aws.amazon.com/blogs/containers/increasing-pod-density-for-windows-nodes-on-amazon-eks/

Please let us know if you have additional questions