Container Network Interface (CNI) in Kubernetes: Cilium’s Role and Cisco’s Acquisition of Isovalent

Welcome to a topic that is crucial for every Kubernetes user: the Container Network Interface (CNI). In this discussion, we not only explore the basics of CNIs but also delve into the specific role of Cilium, a leading CNI known for its advanced features and significance in modern Kubernetes implementations. Particularly interesting is the recent development in the CNI landscape – the acquisition of Isovalent, the Swiss company behind Cilium, by the American networking giant Cisco.

This acquisition is noteworthy not only because of Cilium’s importance for Kubernetes clusters but also due to the potential impact on the open-source community and the European technology market. With this article, we aim to provide a comprehensive insight into the topic, from the technical aspects of a CNI to the potential consequences of this acquisition for the global technology market.

Our goal is to convey a clear understanding of what CNI means, why Cilium plays a vital role in the Kubernetes world, and what impact Cisco’s acquisition of Isovalent might have. We will also discuss the significance of this development for the European sovereignty concept and the future of the open-source version of Cilium.

Basics of Container Network Interface (CNI)

The Kubernetes ecosystem is multi-layered and complex. A central element in this world is the Container Network Interface, better known as CNI. CNIs are crucial for network communication within Kubernetes clusters. They provide the necessary infrastructure for containers running in a Kubernetes cluster to communicate with each other. This communication is essential for the operation and scalability of containerized applications.

A CNI in Kubernetes is essentially a plugin that establishes network connections for containers. When a container is launched in a pod, the CNI is activated to configure a network connection for that container. This includes tasks such as assigning IP addresses, setting up network paths, and implementing security policies. The special feature of CNIs is their flexibility; they allow users to tailor the network requirements of their applications in a way that fits their specific infrastructure.

Why do we need CNIs in Kubernetes environments?

In a Kubernetes environment, the CNI plays a crucial role. Without an efficient CNI, containers could not communicate with each other, significantly disrupting the interaction of the various services and applications running in a Kubernetes cluster. A powerful CNI ensures that network resources are used efficiently and that communication between containers is secure and stable. In a world where application performance and availability are of central importance, a reliable CNI is indispensable.

Overview of various CNI solutions and their roles

There are numerous CNI solutions on the market, each with its own strengths and peculiarities. Some popular CNIs include:

• Cilium: Known for its use of eBPF to provide advanced security and network functionalities.
• Calico: Often appreciated for its powerful network policies and simple implementation methods.
• Flannel: Popular for its simplicity and efficiency, especially in smaller or less complex environments.
• Weave: Another popular CNI known for its robust and user-friendly configuration.

Each of these CNIs brings its own advantages and specific features, making it suitable for different use cases and environments. The choice of the right CNI depends heavily on the specific requirements and goals of the respective Kubernetes cluster.

In the following sections, we will delve deeper into the topic of Cilium, particularly regarding its role in Kubernetes and the recent developments surrounding Cisco’s acquisition of Isovalent.

What makes Cilium so special?

Cilium has established itself as one of the most advanced CNIs in the Kubernetes ecosystem. Developed by the Swiss company Isovalent, Cilium stands out through the use of eBPF technology (extended Berkeley Packet Filter). eBPF allows Cilium to optimize network throughput, security, and observability in ways that are not possible with traditional methods. Core features of Cilium include:

• Application-level network policies: Cilium can apply security policies based on Kubernetes labels instead of traditional IP addresses, enabling fine-grained security control.
• Load balancing: Through eBPF technology, Cilium can make load balancing more efficient by redirecting traffic directly at the kernel level.
• Network and security observability: Cilium provides insights into network traffic, which is essential for security monitoring and troubleshooting.

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    <p>At Ayedo, we chose Cilium for our Managed Kubernetes product <a href="/products/fleet/">Ayedo Fleet</a> for several reasons. One of the main reasons is the eBPF-based architecture, which ensures high performance and security. These features are particularly important to us as a reliable and secure network environment is of utmost interest to our customers. Additionally, Cilium enables:</p>

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