Chapter 11. Configuring the cluster network range

Procedure

1. To obtain the cluster network range and host prefix for your cluster, enter the following command:

   $ oc get network.operator.openshift.io \
     -o jsonpath="{.items[0].spec.clusterNetwork}"

   Example output

   [{"cidr":"10.217.0.0/22","hostPrefix":23}]

2. To expand the cluster network IP address range, enter the following command. Use the CIDR IP address range and host prefix returned from the output of the previous command.

   $ oc patch Network.config.openshift.io cluster --type='merge' --patch \
     '{
       "spec":{
         "clusterNetwork": [ {"cidr":"<network>/<cidr>","hostPrefix":<prefix>} ],
         "networkType": "OVNKubernetes"
       }
     }'

   where:

   <network>

   Specifies the network part of the cidr field that you obtained from the previous step. You cannot change this value.

   <cidr>

   Specifies the network prefix length. For example, 14. Change this value to a smaller number than the value from the output in the previous step to expand the cluster network range.

   <prefix>

   Specifies the current host prefix for your cluster. This value must be the same value for the hostPrefix field that you obtained from the previous step.

   Example command

   $ oc patch Network.config.openshift.io cluster --type='merge' --patch \
     '{
       "spec":{
         "clusterNetwork": [ {"cidr":"10.217.0.0/14","hostPrefix": 23} ],
         "networkType": "OVNKubernetes"
       }
     }'

   Example output

   network.config.openshift.io/cluster patched

3. To confirm that the configuration is active, enter the following command. It can take up to 30 minutes for this change to take effect.

   $ oc get network.operator.openshift.io \
     -o jsonpath="{.items[0].spec.clusterNetwork}"

   Example output

   [{"cidr":"10.217.0.0/14","hostPrefix":23}]