Configuring the node port <strong>service</strong> range | Networking

Expanding the node port range
Additional resources

During cluster installation, you can configure the node port range to meet the requirements of your cluster. After cluster installation, only a cluster administrator can expand the range as a postinstallation task. If your cluster uses a large number of node ports, consider increasing the available port range according to the requirements of your cluster.

If you do not set a node port range during cluster installation, the default range of 30000-32768 applies to your cluster. In this situation, you can expand the range on either side, but you must preserve 30000-32768 within your new port range.

Red Hat has not performed testing outside the default port range of 30000-32768. For ranges outside the default port range, ensure that you test to verify the expanding node port range does not impact your cluster. In particular, ensure that there is:

No overlap with any ports already in use by host processes
No overlap with any ports already in use by pods that are configured with host networking

If you expanded the range and a port allocation issue occurs, create a new cluster and set the required range for it.

If you expand the node port range and OpenShift CLI (oc) stops working because of a port conflict with the OKD API server, you must create a new cluster.

Expanding the node port range

You can expand the node port range for your cluster. After you install your OKD cluster, you cannot shrink the node port range on either side of the currently configured range.

Red Hat has not performed testing outside the default port range of 30000-32768. For ranges outside the default port range, ensure that you test to verify that expanding your node port range does not impact your cluster. If you expanded the range and a port allocation issue occurs, create a new cluster and set the required range for it.

Prerequisites

Installed the OpenShift CLI (oc).
Logged in to the cluster as a user with cluster-admin privileges.
You ensured that your cluster infrastructure allows access to the ports that exist in the extended range. For example, if you expand the node port range to 30000-32900, your firewall or packet filtering configuration must allow the inclusive port range of 30000-32900.

Procedure

To expand the range for the serviceNodePortRange parameter in the network.config.openshift.io object that your cluster uses to manage traffic for pods, enter the following command:

$ oc patch network.config.openshift.io cluster --type=merge -p \
  '{
    "spec":
      { "serviceNodePortRange": "<port_range>" }
  }'

where:

<port_range>: specifies your expanded range, such as 30000-32900.

You can also apply the following YAML to update the node port range:

apiVersion: config.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  serviceNodePortRange: "<port_range>"
# ...

Example output

network.config.openshift.io/cluster patched

Verification

To confirm that the updated configuration is active, enter the following command. The update can take several minutes to apply.

$ oc get configmaps -n openshift-kube-apiserver config \
  -o jsonpath="{.data['config\.yaml']}" | \
  grep -Eo '"service-node-port-range":["[[:digit:]]+-[[:digit:]]+"]'

Example output

"service-node-port-range":["30000-32900"]

Configuring the node port service range

Expanding the node port range

Additional resources