KubeCon + CloudNativeCon North America 2024

Multicast is a popular networking technology used in finance, telecommunications, and media CDNs, among others to efficiently replicate and deliver data streams to multiple clients. However, this advantage can be overshadowed by the complexity involved in configuring the necessary infrastructure leaving the overworked platform team rather than the end users seeing double. To combat this complexity, Cilium explored using eBPF to implement pod-to-pod multicast delivery within a Kubernetes cluster. This talk will provide both a high and low level understanding of how eBPF can be used to implement multicast delivery. It will discuss how Cilium’s multicast works and the hurdles faced by the project along the way. By the end of this talk the audience will have a better understanding of how multicast functions, how eBPF can be used in-place of traditional multicast infrastructure, and how Cilium can be used as a multicast-enabled CNI, letting your audience - and not you- see double.