Kubernetes network plugins
Kubernetes has a network plugin system since networking is so diverse and different people would like to implement it in different ways. Kubernetes is flexible enough to support any scenario. The primary network plugin is CNI, which we will discuss in depth. But Kubernetes also comes with a simpler network plugin called Kubenet. Before we go over the details, let’s get on the same page with the basics of Linux networking (just the tip of the iceberg). This is important because Kubernetes networking is built on top of standard Linux networking and you need this foundation to understand how Kubernetes networking works.
Basic Linux networking
Linux, by default, has a single shared network space. The physical network interfaces are all accessible in this namespace. But the physical namespace can be divided into multiple logical namespaces, which is very relevant to container networking.