# flannel-io/flannel

flannel is a network fabric for containers, designed for Kubernetes

Repository: https://github.com/flannel-io/flannel
Canonical: https://ross.abutalabs.com/products/flannel
Language: Go
License: Apache-2.0
License Family: permissive
Topics: kubernetes, network, overlay-network, docker, go, flannel, subnet, docker-image
Last push: 2026-08-24T08:38:16+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 96, longevity 100
- inputs: {"age_days": 4437, "days_push": 9, "days_rel": 26, "gap_med": 29, "n_releases_24m": 24}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 9523, forks 2886 (observed 2026-08-28T04:10:31.649729+00:00)

## What it is
Flannel is a simple layer 3 network fabric for containers, designed primarily for Kubernetes. It runs a small agent (flanneld) on each host to allocate subnet leases and forwards pod traffic between nodes using backends like VXLAN, providing a CNI plugin for Kubernetes.

## Use cases
- set up pod networking in a Kubernetes cluster
- provide a CNI plugin for container networking
- configure an overlay network with VXLAN between hosts
- give each container a unique routable IP across nodes
- network a lightweight cluster like K3s
- replace complex port mapping with routable pod IPs

## When to choose
- you want a simple, easy-to-operate Kubernetes network fabric
- you run K3s or a distribution that defaults to flannel
- you need basic pod-to-pod connectivity without heavy features
- you prefer a single small binary agent per host

## When to avoid
- you need built-in network policy enforcement (flannel requires external controllers like Calico or Cilium)
- you need advanced features like eBPF dataplane, service mesh, or encryption
- you need IPv6-only networking as your primary requirement
- you want a feature-rich CNI with extensive traffic control

## Facets
- artifact type: infra-config
- maturity: stable
- function: networking, container-orchestration, deployment
- domain: networking, cloud-computing
- platform: go, cloud
- tags: cni-plugin, overlay-network, vxlan, kubernetes-networking, subnet-allocation, pod-networking, containers, devops, linux, kubernetes, docker

## Member repositories
- flannel-io/flannel (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:31.649729+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:21:59.647632+00:00, confidence not recorded.
  - readme: https://github.com/flannel-io/flannel (fetched 2026-08-28T04:10:31.649729+00:00, sha b0045c83e8c9)
- Data as of 2026-08-30T08:39:29.467469+00:00.