Simplifying Kubernetes with Cilium: A Calico Replacement



June 20, 2024

Cilium vs. Calico

Do you want to choose a powerful plugin for your network to run on Kubernetes? If yes, then you are at the right destination. Here we will let you know the difference between two powerful plugins: Cilium Vs Calico: Which is better for Kubernetes security?

Kubernetes is like the superhero of the digital world. It helps organizations manage their applications, making everything run smoothly. But as Kubernetes gets more complex, we need better tools to understand what’s going on there. That’s where Cilium comes into play. In this blog, we’ll talk about Cilium as a replacement for Calico and how it can help you see better in your Kubernetes world.

Cilium vs. Calico: Which is better for Kubernetes Security?

Kubernetes relies on networking solutions like Calico and Cilium to handle container communications, network security, and observability. Let’s dissect the key differences between these two contenders to determine which one is better equipped to enhance observability within your Kubernetes cluster.

Must Read: Managing and Monitor Apache Spark on Kubernetes

Calico Vs Cilium: Network Safety in Kubernetes 

Calico: Calico is good at keeping your network safe in Kubernetes. It uses simple but effective rules to make sure your apps are talking to each other safely. These rules are based on things like IP addresses, subnets, and ports.

Cilium: Cilium takes network safety to the next level. It can protect your apps at a much deeper level, including the seventh layer (L7). This is super important when you have modern apps with lots of tiny parts.

Understand Calico & Its Features: Policy-Driven Network and Security

Calico is a popular open-source project providing a suite of tools for Kubernetes networking and network policy enforcement. It offers:

  • 1. Policy Enforcement: Calico focuses on maintaining the network security policies at the pod level to ensure granular control over communication between containers. 
  • 2. Service Discovery: It facilitates service discovery allowing pods to search and connect to other devices within the cluster. 
  • 3. IP Address Management: Calico simplifies IP address allocation and management for pods within the Kubernetes cluster.

However, Calico’s configuration can involve additional components like a dedicated network policy controller, potentially increasing complexity.

Cilium & Its Features: A Lightweight and Secure Alternative

Cilium works as a different approach that leverages the eBPF technology for secure networking. It simplifies multiple things including: 

  • 1. Reduced Components: Cilium works as a single agent that eliminates the need for a separate network policy controller. This moves to a streamlined deployment and works on managing experience. 
  • 2. Enhanced Security: By working at the eBPF level, Cilium offers solid integration with the Linux Kernel that leads to security enforcement. 
  • 3. Observability: It provides rich observability tools including Hubble that offer deep insights into network traffic within your cluster. 

How to Choose Networking Plugin Cilium Vs Calico for Kubernetes?

Both Calico and Cilium are considered excellent choices for Kubernetes networking. There are some factors you should consider before making any decision. The factors are:

Deployment Complexity:

  • 1. Calico: Stays on multiple components that include a dedicated network policy controller. This will add complexity during the setup stage and ongoing management. 
  • 2. Cilium: Cilium works as a single agent that streamlines the deployment stage and reduces the moving parts. This can be easier for smaller teams or for those who are new in the field of Kubernetes networking. 

Security Focus:

  • 1. Calico: Gives strong network policy enforcement and operates at a slightly higher level than the kernel.
  • 2. Cilium: By leveraging the eBPF technology for deep integration with the Linux kernel, potentially leading to more robust security capabilities. This is essential for highly sensitive deployments.

Performance and Observability:

  • 1. Calico: Generally performs well, but Cilium’s eBPF approach might offer slight performance advantages in certain scenarios.
  • 2. Cilium: Provides Hubble, a powerful observability tool that offers detailed insights into network traffic within your cluster. This can be invaluable for troubleshooting and monitoring network health.


  • 1. Calico: Highly scalable and well-suited for large deployments with complex network requirements.
  • 2. Cilium: Also scales well, but its reliance on eBPF maps might introduce limitations in exceptionally large clusters with a massive number of identities or entities.

Existing Infrastructure:

  • 1. Calico: If you already have a Calico deployment, migrating to Cilium might require additional effort. However, they can co-exist during a transition phase, allowing you to migrate gradually.

Team Expertise:

  • 1. Calico: Easier to manage teams without prior eBPF experience, as it uses established network technologies.
  • 2. Cilium: This may require familiarity with eBPF for optimal configuration and troubleshooting.

In short, we can say that:

  • 1. Choose Calico if:
    • You already have a Calico deployment and prefer a familiar approach.
    • You need maximum scalability for exceptionally large clusters.
    • Your team lacks eBPF experience.
  • 2. Choose Cilium if:
    • You prioritize a streamlined deployment with a single agent.
    • Enhanced security at the kernel level is a top concern.
    • You value advanced observability with tools like Hubble.
    • Your team is comfortable with eBPF technology.

The choice between Cilium Vs Calico depends on you based on your specific priorities and environment. You must consider the deployment size, security requirements, team expertise, and the existing business infrastructure before making a decision call. Both Cilium and Calico offer excellent documentation and have wider community support to explore the resources. 

Why Watching Your Kubernetes Is Important?

“Observability” is a fancy word for keeping an eye on your Kubernetes. Why is this so important?

  • 1. Fixing Problems: In a big Kubernetes world, things can go wrong. Apps can act weird, or the network can get crazy busy. Observability helps you quickly figure out what’s broken and how to fix it.
  • 2. Saving Resources: Using resources wisely is like saving money. When you can see what your apps need, you can give them just enough resources, not too much. This saves you money in the long run.
  • 3. Staying Safe: Security is a big deal, especially in today’s apps. Observability helps you spot any bad guys trying to mess with your apps, protecting you from nasty surprises.

Also Read: Simplify Cluster Deployment on Kubernetes

Cilium’s Superpowers for Watching

Cilium is like a superhero when it comes to keeping an eye on your Kubernetes. Here are some of its cool features:

  • 1. See More Clearly: Cilium can dig deep into the traffic between your apps, giving you a clear view of what’s going on. This is like having a super magnifying glass to spot issues and make things faster.
    One powerful tool in Cilium’s arsenal is Hubble, allowing you to visualize how services are laid out in the cluster seamlessly. This provides an intuitive way to understand the architecture and relationships between different services, enhancing overall observability.
  • 2. Understand Apps Better: Cilium is like a translator for your apps. It understands what they’re saying and can tell you if everything is okay. This is great for finding problems in complex apps.
  • 3. Lock Your Apps Safely: Cilium makes sure your apps only talk to the right friends. It’s like a bouncer at the club, checking everyone’s ID to keep the troublemakers out. Unlike some alternatives, Cilium enables service mesh capabilities without the need for resource-heavy sidecar containers in the cluster. This ensures efficient resource utilization without compromising on the benefits of a service mesh architecture, making Cilium an attractive choice for performance-conscious environments.
  • 4. Follow the Clues: With Cilium, you can follow the breadcrumbs in your apps. It works with tracing tools that help you track how requests move through your apps. This is super useful for finding where things slow down.
  • 5. Stay Safe in the Cloud: Cloud apps need extra protection. Cilium’s L7 security and visibility help you stay safe from modern threats. It’s like having a guard dog for your apps.
  • 6. Easy Rules: Cilium lets you create rules for your network that are easy to understand and manage. This way, you can keep your network safe without getting a headache. In comparison to Calico, Cilium provides a straightforward method for conducting network tests to ensure everything operates seamlessly at the network level. This feature is invaluable for preemptively identifying and addressing any potential networking issues, contributing to the robustness of your Kubernetes environment.


In the ever-evolving landscape of Kubernetes, observability plays a crucial role in maintaining the health and security of your applications. After understanding the Cilium Vs Calico features for Kubernetes networking & security, we will be able to understand that Calico has been a trusty friend for network security, Cilium is like the new superhero in town when it comes to observing what’s happening in your Kubernetes world.

If you’re thinking about using Cilium instead of Calico, remember to think about your needs. Cilium is great for those who want to understand their Kubernetes better, boost security, and make sure their apps run smoothly. With Cilium, you get super tools to make your Kubernetes world even more fantastic, ensuring your apps are safe, fast, and reliable.

If you’re looking for the best DevOps consulting company, connect with Ksolves for expert guidance on optimizing your Kubernetes environment!

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ksolves Team

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