Kubernetes is a technology that helps you get the most out of your hardware. Containers are deployed on several nodes, making sure that every CPU cycle, every byte of memory, and every block of storage is not wasted. However, this is no easy task. Several challenges must be addressed when designing how the cluster will handle networking among containers:

• How the same pod containers can communicate with each other. This is handled through the loopback interface. For more information, please refer to our earlier article Kubernetes pods 101.
• How a container can contact a service. This is managed through Kubernetes Services.
• How the cluster can receive external traffic. This topic is also covered by Kubernetes Services.
• How a pod can contact another pod on the same node or on a different one, which is the main focus of this article.