Dual-stack Networking documentation should include the need for --node-ip listing both host IP versions

[kable-wilmoth]

If you are used to default installing and running K3s with minimal tweaks and everything 'just works' you will probably get hung up trying to enable IPv6 (dual stack)

Docs:
https://docs.k3s.io/networking/basic-network-options#dual-stack-ipv4--ipv6-networking
If you follow the documentaiton of adding an updated pod and service CIDR w/ both v4 and v6 address, K3S will fail to start up.
The failure is "cluster-cidr and node-ip must share the same IP version (IPv4, IPv6 or dual-stack)"

The resolution to this error is additionally adding
--node-ip=,

The server will now start.
You can then see that the node is using both v4 and v6 addresses
kubect get node -o yaml

So if this is required, should this be added to the dual stack docs?

For anyone else who finds this, I thought the dual stack instructions were not working because my pod never showed the v6 IP address with:
kubectl get pods -o wide
It was actually working the entire time but only the, I guess, primary IP version will be shown.
I just simply needed to look at the networks attached to the pod to realize both v4 and v6 were being assigned

[brandond]

Please use the issue template. What version of k3s are you using? My understanding is that this shouldn't be necessary in recent releases, unless you are intentionally passing a single stack node IP while trying to also use dual stack cluster and service CIDRs.

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