Overview
Flannel is one of the oldest and simplest CNI plugins. It creates an overlay network that gives each node a subnet, from which pods are assigned IP addresses. It is designed for ease of use rather than advanced features.
Key Characteristics
- Overlay Network: Typically uses VXLAN to encapsulate pod traffic and send it over the host network.
- Simplicity: Very easy to install and requires minimal configuration.
- No Network Policy: Flannel itself does not support Kubernetes Network Policies (though it can be used with other tools like Calico for this purpose).
Use Case
Great for development environments, small clusters, or situations where simplicity is more important than advanced security or performance.