OpenShift supports third-party Container Network Interfaces (CNIs) to provide advanced networking capabilities. However, there are specific requirements and limitations when using third-party CNIs. Let's analyze each statement:
A . In OpenShift, you can remove and install a third-party CNI after the cluster has been deployed.
Incorrect:
OpenShift does not allow you to change or replace the CNI plugin after the cluster has been deployed. The CNI plugin must be specified during the initial deployment.
B . In OpenShift, you must specify the third-party CNI to be installed during the initial cluster deployment.
Correct:
OpenShift requires you to select and configure the desired CNI plugin (e.g., Calico, Cilium) during the initial cluster deployment. Once the cluster is deployed, changing the CNI plugin is not supported.
C . OpenShift does not support third-party CNIs.
Incorrect:
OpenShift supports third-party CNIs as alternatives to the default SDN (Software-Defined Networking) solution. This flexibility allows users to choose the best networking solution for their environment.
D . In OpenShift, you can have multiple third-party CNIs installed simultaneously.
Incorrect:
OpenShift does not support running multiple CNIs simultaneously. Only one CNI plugin can be active at a time, whether it is the default SDN or a third-party CNI.
Why This Statement?
Initial Configuration Requirement: OpenShift enforces the selection of a CNI plugin during the initial deployment to ensure consistent and stable networking across the cluster.
Stability and Compatibility: Changing the CNI plugin after deployment could lead to network inconsistencies and compatibility issues, which is why it is not allowed.
JNCIA Cloud Reference:
The JNCIA-Cloud certification covers OpenShift networking, including the use of third-party CNIs. Understanding the limitations and requirements for CNI plugins is essential for deploying and managing OpenShift clusters effectively.
For example, Juniper Contrail can be integrated as a third-party CNI in OpenShift to provide advanced networking and security features, but it must be specified during the initial deployment.
Reference:
OpenShift Documentation: Third-Party CNIs
Juniper JNCIA-Cloud Study Guide: OpenShift Networking