Menu Close

12.5.9. Modifying advanced network configuration parameters

You can modify the advanced network configuration parameters only before you install the cluster. Advanced configuration customization lets you integrate your cluster into your existing network environment by specifying an MTU or VXLAN port, by allowing customization of kube-proxy settings, and by specifying a different mode for the openshiftSDNConfig parameter.


Modifying the OpenShift Container Platform manifest files created by the installation program is not supported. Applying a manifest file that you create, as in the following procedure, is supported.


  • Create the install-config.yaml file and complete any modifications to it.
  • Create the Ignition config files for your cluster.


  1. Use the following command to create manifests:

    $ ./openshift-install create manifests --dir=<installation_directory> 1
    For <installation_directory>, specify the name of the directory that contains the install-config.yaml file for your cluster.
  2. Create a file that is named cluster-network-03-config.yml in the <installation_directory>/manifests/ directory:

    $ touch <installation_directory>/manifests/cluster-network-03-config.yml 1
    For <installation_directory>, specify the directory name that contains the manifests/ directory for your cluster.

    After creating the file, several network configuration files are in the manifests/ directory, as shown:

    $ ls <installation_directory>/manifests/cluster-network-*

    Example output


  3. Open the cluster-network-03-config.yml file in an editor and enter a CR that describes the Operator configuration you want:

    kind: Network
      name: cluster
    spec: 1
      - cidr:
        hostPrefix: 23
        type: OpenShiftSDN
          mode: NetworkPolicy
          mtu: 1450
          vxlanPort: 4789
    The parameters for the spec parameter are only an example. Specify your configuration for the Cluster Network Operator in the CR.

    The CNO provides default values for the parameters in the CR, so you must specify only the parameters that you want to change.

  4. Save the cluster-network-03-config.yml file and quit the text editor.
  5. Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program deletes the manifests/ directory when creating the cluster.
  6. Remove the Kubernetes manifest files that define the control plane machines and compute machineSets:

    $ rm -f openshift/99_openshift-cluster-api_master-machines-*.yaml openshift/99_openshift-cluster-api_worker-machineset-*.yaml

    Because you create and manage these resources yourself, you do not have to initialize them.

    • You can preserve the MachineSet files to create compute machines by using the machine API, but you must update references to them to match your environment.