Network connectivity upgrade error

Learn how to work around network connectivity issues when upgrading the product.

Problem

For Red Hat® OpenShift® Container Platform version 4.10 and earlier, the Container Network Interface (CNI) default was OpenShiftSDN. However, from version 4.11 onwards, Red Hat OpenShift Container Platform uses the OVNKubernetes network plugin by default, for new installations. When you upgrade Netcool® Operations Insight® on OpenShift, network connectivity issues might occur. For example, some ITNM Observers might not be able to connect.

The Red Hat OpenShift Networking network plugin is selected during installation (OpenShiftSDN or OVNKubernetes). This value cannot be changed after cluster installation. From Red Hat OpenShift Container Platform version 4.12 onwards, the OVNKubernetes Container Network Interface (CNI) uses the 100.64.0.0/16 IPv4 subnet internally. For more information, see Cluster Network Operator external icon and About the OVN-Kubernetes network plugin external icon in the Red Hat OpenShift Container Platform documentation.

Solution

Redeploy your cluster with OpenShiftSDN or redeploy the cluster with OVNKubernetes and customize the address range that it uses internally.

If your existing network infrastructure overlaps with the 100.64.0.0/16 IPv4 subnet, you can specify a different IP address range for internal use by OVNKubernetes. You must ensure that the IP address range does not overlap with any other subnet used by your Red Hat OpenShift Container Platform installation. The IP address range must be larger than the maximum number of nodes that can be added to the cluster..