Flannel
Open-source layer 3 networking for Kubernetes clusters.
At a glance
- Editor scoreNot yet scored
- PricingFree plan
- Best forStraightforward Kubernetes cluster networking
- Free planYes
- Paid fromNone
- Network policiesYes
- Facts checked20 Sep 2026
Where it wins
- Free and open-source with no paid tier structure
- VXLAN, host-gw, WireGuard, and IPsec backend options
- Kubernetes CNI with subnet and lease management
Where it doesn't
- Network policy enforcement uses a separate controller
- Dual-stack support applies only to selected backends
- Feature scope is narrower than policy-focused CNIs
Our verdict on Flannel
Flannel is open-source infrastructure software for container networking, designed primarily for Kubernetes clusters. It runs a flanneld agent on each host, allocates per-host subnets, manages leases, and provides Layer 3 IPv4 connectivity between nodes. Its Kubernetes CNI plugin can also work with Docker, making it a practical fit for teams that want straightforward cluster networking without a hosted service or paid plan structure.
The main technical choice is the transport backend. Flannel supports VXLAN, host-gw, WireGuard, and IPsec, so operators can select an approach that matches their cluster network and encryption requirements. Configuration can use the Kubernetes API or etcd, and the project includes Helm integration guidance. Dual-stack IPv4 and IPv6 support is available for selected backends rather than across every option, so backend selection matters for clusters that require both protocols.
Flannel keeps its core scope focused: subnet allocation, node-to-node transport, and Kubernetes CNI integration. Network policy support is available through the Kubernetes SIGs network policy controller deployed alongside Flannel, rather than through native enforcement in the flanneld binary. That makes Flannel a sensible choice for teams prioritizing a simple networking layer and flexible backend options. Teams that need policy enforcement as a central, native capability should consider a policy-focused CNI instead.
Flannel pricing
Flannel fact sheet
| Free plan | Yes |
|---|---|
| Paid from | None |
| CNI plugin | Yes |
| Network policies | Yes |
| Egress control | Not verified |
| Multi-cluster networking | Not verified |
| Encryption in transit | Yes |
| Supported platforms | Kubernetes, Docker, Linux, Windows |
| Deployment | Self-hosted |
| Platforms | Linux, Windows |
| Support | Community, Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 4 integrations: Kubernetes, etcd, Docker, Helm |
| Pricing | Free plan |
| Website | github.com |
| Facts checked | 20 Sep 2026 |
Flannel integrations
Flannel lists 4 integrations on its own site.
- Kubernetes
- etcd
- Docker
- Helm
Alternatives to Flannel
- CiliumA broad open-source networking and observability layer for Kubernetes environments.—
- Calico Open SourceA free, broad Kubernetes networking stack with policy, encryption, and multi-cluster support.—
- AntreaA strong open-source choice for advanced Kubernetes networking, policy, and visibility.—
See all Flannel alternatives →
Used Flannel? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used Flannel for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
Flannel is listed in our Container Networking Software directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/flannel/"><img src="https://www.itechguides.com/best/badge/flannel.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Sep 2026
Advertiser disclosure: iTechGuides is reader-supported. We may earn a commission when you click some links. It never changes a score or a verdict. How we rank.