Cilium works great out of the box, but tweaking a few options will ensure you get the best performance as your clusters grow in size. While Cilium abstracts away a lot of complexity, users are provided with several knobs to control the underlying systems wherever necessary. This talk will quickly brush up on how Cilium interacts with Linux, Kubernetes and cloud provider network stacks and then dive into some of the challenges you might encounter running Cilium in large clusters. For example, over time, you might need to reevaluate rate limiting across the board to avoid cascading failures. You will need to carefully plan for IP address management, tune the operating system or take advantage of new features from cloud providers. Since Cilium is a critical piece of your infrastructure, we’ll talk about what health metrics to keep a close eye on. We’ll also discuss some best practices for deploying and validating your rollouts with out of the box connectivity tests.