Chapter 5. Converting to IPv4/IPv6 dual-stack networking

Procedure

1. To specify IPv6 address blocks for cluster and service networks, create a YAML configuration patch file that has a similar configuration to the following example:

   - op: add
     path: /spec/clusterNetwork/-
     value:
       cidr: fd01::/48
       hostPrefix: 64
   - op: add
     path: /spec/serviceNetwork/-
     value: fd02::/112

   where:

   /spec/clusterNetwork/-

   Specifies an object with the cidr and hostPrefix parameters. The host prefix must be 64 or greater. The IPv6 Classless Inter-Domain Routing (CIDR) prefix must be large enough to accommodate the specified host prefix.

   /spec/serviceNetwork/-

   Specifies an IPv6 CIDR with a prefix of 112. Kubernetes uses only the lowest 16 bits. For a prefix of 112, IP addresses are assigned from 112 to 128 bits.

2. Patch the cluster network configuration by entering the following command in your CLI:

   $ oc patch network.config.openshift.io cluster \
     --type='json' --patch-file <file>.yaml

   For <file>, specify the name of the YAML file you created.

   Example output

   network.config.openshift.io/cluster patched

3. On installer-provisioned infrastructure where you added IPv6 VIPs for API and Ingress services, complete the following steps:

   1. Specify IPv6 VIPs for API and Ingress services for your cluster. Create a YAML configuration patch file that has a similar configuration to the following example:

      - op: add
        path: /spec/platformSpec/baremetal/machineNetworks/-
        value: fd2e:6f44:5dd8::/64
      - op: add
        path: /spec/platformSpec/baremetal/apiServerInternalIPs/-
        value: fd2e:6f44:5dd8::4
      - op: add
        path: /spec/platformSpec/baremetal/ingressIPs/-
        value: fd2e:6f44:5dd8::5

      where:

      /spec/platformSpec/baremetal/machineNetworks/-

      Specifies an address block for the machineNetwork network where your machines operate. You must select both API and Ingress IP addresses for the machine network.

      /spec/platformSpec/baremetal/apiServerInternalIPs/-

      Specifies each file path according to your platform. The example demonstrates a file path on a bare metal platform.

   2. Patch the infrastructure by entering the following command in your CLI:

      $ oc patch infrastructure cluster \
        --type='json' --patch-file <file>.yaml

      For <file>, specify the name of the YAML file you created.

      Example output

      infrastructure/cluster patched

Verification

1. Show the cluster network configuration by entering the following command in your CLI:

   $ oc describe network

2. Verify the successful installation of the patch on the network configuration by checking that the cluster network configuration recognizes the IPv6 address blocks that you specified in the YAML file.

   Example output

   # ...
   Status:
     Cluster Network:
       Cidr:               10.128.0.0/14
       Host Prefix:        23
       Cidr:               fd01::/48
       Host Prefix:        64
     Cluster Network MTU:  1400
     Network Type:         OVNKubernetes
     Service Network:
       172.30.0.0/16
       fd02::/112
   # ...

3. Complete the following additional tasks for a cluster that runs on installer-provisioned infrastructure:

   1. Show the cluster infrastructure configuration by entering the following command in your CLI:

      $ oc describe infrastructure

   2. Verify the successful installation of the patch on the cluster infrastructure by checking that the infrastructure recognizes the IPv6 address blocks that you specified in the YAML file.

      Example output

      # ...
      spec:
      # ...
        platformSpec:
          baremetal:
            apiServerInternalIPs:
            - 192.168.123.5
            - fd2e:6f44:5dd8::4
            ingressIPs:
            - 192.168.123.10
            - fd2e:6f44:5dd8::5
      status:
      # ...
        platformStatus:
          baremetal:
            apiServerInternalIP: 192.168.123.5
            apiServerInternalIPs:
            - 192.168.123.5
            - fd2e:6f44:5dd8::4
            ingressIP: 192.168.123.10
            ingressIPs:
            - 192.168.123.10
            - fd2e:6f44:5dd8::5
      # ...

Procedure

1. Edit the networks.config.openshift.io custom resource (CR) by running the following command:

   $ oc edit networks.config.openshift.io

2. Remove the IPv4 or IPv6 configuration that you added to the cidr and the hostPrefix parameters from completing the "Converting to a dual-stack cluster network " procedure steps.