IPv4/IPv6 Dual-stack

Kubernetes supports IPv4-only, IPv6-only, and dual-stack networking configurations. For more details, refer to the official Kubernetes documentation.

Installing Rancher on IPv6-Only or Dual-Stack Clusters

Rancher can run on clusters using:

  • IPv4-only

  • IPv6-only

  • Dual-stack (IPv4 + IPv6)

When you install Rancher on an IPv6-only cluster, it can communicate externally only over IPv6. This means it can provision:

  • IPv6-only clusters

  • Dual-stack clusters (IPv4-only downstream clusters are not possible in this case)

When you install Rancher on a dual-stack cluster, it can communicate over both IPv4 and IPv6, and can therefore provision:

  • IPv4-only clusters

  • IPv6-only clusters

  • Dual-stack clusters

For installation steps, see the guide: Installing and Upgrading Rancher.

Requirement for the Rancher Server URL

When provisioning IPv6-only downstream clusters, the Rancher Server URL must be reachable over IPv6 because downstream nodes connect back to the Rancher server using IPv6.

Provisioning IPv6-Only or Dual-Stack Clusters

You can provision RKE2 and K3s Node driver (machine pools) or Custom cluster (existing hosts) clusters using IPv4-only, IPv6-only, or dual-stack networking.

Network Configuration

To enable IPv6-only or dual-stack networking, you must configure:

  • Cluster CIDR

  • Service CIDR

  • Stack Preference

Configuration references:

Support for Windows

Kubernetes on Windows:

Feature Support Status

IPv6-only clusters

Not supported

Dual-stack clusters

Supported

Services

Limited to a single IP famil

For more information, see the Kubernetes Documentation.

K3s does not support Windows (FAQ)

RKE2 supports Windows, but requires using either Calico or Flannel as the CNI. Note that Windows installations of RKE2 do not support dual-stack clusters using BGP. For more details, see RKE2 Network Options.

Provisioning Node Driver Clusters

Rancher currently supports assigning IPv6 addresses in node driver clusters with:

Support for additional providers will be introduced in future releases.

DigitalOcean Limitation

Creating an IPv6-only cluster using the DigitalOcean node driver is currently not supported. For more details, please see rancher/rancher#52523.

Infrastructure Requirements

Cluster nodes must meet the requirements listed in the Node Requirements for Rancher Managed Clusters.

Machine pool configuration guides:

Provisioning Custom Clusters

To provision on your own nodes, follow the instructions in Provision Kubernetes on Existing Nodes.

  • Node Public IP and Node Private IP fields accept IPv4, IPv6, or both (comma-separated). > Example: 10.0.0.5,2001:db8::1

  • In IPv6-only and dual-stack clusters, specify the node’s IPv6 address as the Private IP.

Infrastructure Requirements

Infrastructure requirements are the same as above for node-driver clusters.

Limitations

Refer to the IPv4/IPv6 Dual-Stack Prime documentation for additional limitations regarding Prime-only IPv6 URL support.

GitHub.com

GitHub.com does not support IPv6. As a result:

  • Any application repositories ( ClusterRepo.catalog.cattle.io/v1 CR) hosted on GitHub.com are not reachable from IPv6-only clusters.

  • Similarly, any non-builtin node drivers hosted on GitHub.com are also not accessible in IPv6-only environments.