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OpenELB
What it is
OpenELB provides external access to Kubernetes LoadBalancer services in bare-metal, edge, and virtualization environments. It assigns service IP addresses from pools defined by Eip objects and supports BGP and Layer 2 load balancing; its documentation also describes VIP mode. In BGP mode, GoBGP publishes service routes to peer routers, and ECMP routing is supported. BGP requires a router that supports BGP and ECMP. Layer 2 needs infrastructure that permits anonymous ARP/NDP packets and forwards traffic through one active node, so failover may briefly interrupt service and bandwidth is limited to that node. VIP mode uses VRRP, is limited to 255 instances per network, and also has brief failover interruptions and a one-node bandwidth limit. OpenELB supports IPv4 only. It can be installed with kubectl manifests or Helm 3 in Kubernetes 1.15 or later. Guides are listed for Kubernetes, K3s, and KubeSphere. The project is vendor-neutral, a CNCF Sandbox Project, and licensed under Apache License 2.0. Support and discussion are directed to the KubeSphere Slack channel.
For and against
For
- Free plan; licensed under Apache License 2.0
- Supports BGP and Layer 2 modes
- Provides IP pools for LoadBalancer services
- Install with kubectl manifests or Helm 3
- Guides cover Kubernetes, K3s, and KubeSphere
Against
- Supports IPv4 only
- Requires Kubernetes 1.15 or later
- Layer 2 traffic uses one active node
- BGP requires a router supporting BGP and ECMP
The verdict
OpenELB offers Kubernetes LoadBalancer IP management and several routing modes for self-hosted infrastructure. Check the router and network prerequisites, IPv4 limit, and mode-specific failover tradeoffs before choosing it.
Who it suits
OpenELB suits teams exposing Kubernetes services from self-hosted bare-metal, edge, or virtualization environments. BGP users need a router that supports BGP and ECMP; Layer 2 users need infrastructure that allows anonymous ARP/NDP packets.
On the record
- Address family limit
- The documentation says OpenELB currently supports only IPv4.openelb.io · read 4 Oct 2026
- BGP configuration
- Users can configure BGP properties through BgpConf and BgpPeer custom resource definitions.openelb.io · read 4 Oct 2026
- BGP prerequisites
- BGP mode requires a router that supports BGP and ECMP; the documentation recommends it for high availability without failover interruptions or bandwidth bottlenecks.openelb.io · read 4 Oct 2026
- Installation
- OpenELB can be installed in a Kubernetes cluster using kubectl manifests or Helm 3.openelb.io · read 4 Oct 2026
- Integrations
- The project lists installation guides for Kubernetes, K3s and KubeSphere.github.com · read 4 Oct 2026
- IP address pools
- Eip objects provide address pools from which OpenELB assigns IP addresses to Kubernetes LoadBalancer services.openelb.io · read 4 Oct 2026
- IP management
- It provides IP address pool management for service load-balancer IPs.openelb.io · read 4 Oct 2026
- Kubernetes requirement
- Installation requires Kubernetes 1.15 or later because OpenELB requires CustomResourceDefinition v1.openelb.io · read 4 Oct 2026
- Layer 2 constraints
- Layer 2 mode requires the infrastructure to allow anonymous ARP/NDP packets, and its traffic forwarding uses one node at a time, which can cause brief interruptions during failover and a single-node bandwidth bottleneck.openelb.io · read 4 Oct 2026
- Layer 2 limitations
- Layer 2 mode forwards traffic through one active node, so failover briefly interrupts services and bandwidth is limited to that node.openelb.io · read 4 Oct 2026
- Layer 2 prerequisites
- Layer 2 mode requires the infrastructure to allow anonymous ARP/NDP packets.openelb.io · read 4 Oct 2026
- License
- OpenELB is licensed under the Apache License, Version 2.0.openelb.io · read 4 Oct 2026
- Load-balancing modes
- It supports BGP mode and Layer 2 mode.openelb.io · read 4 Oct 2026
- Project origin
- OpenELB is a KubeSphere sub-project; its repository says it was originally created by KubeSphere and is now vendor neutral and a CNCF Sandbox Project.github.com · read 4 Oct 2026
- Project status
- The repository says OpenELB was originally created by KubeSphere and is a vendor-neutral CNCF Sandbox Project.github.com · read 4 Oct 2026
- Purpose
- OpenELB exposes Kubernetes LoadBalancer services to external access in bare-metal, edge, and virtualization environments.openelb.io · read 4 Oct 2026
- Router requirements
- BGP mode requires a router that supports BGP and ECMP; the documentation suggests Layer 2 or VIP mode when those are unavailable.openelb.io · read 4 Oct 2026
- Routing
- OpenELB supports ECMP routing and load balancing.openelb.io · read 4 Oct 2026
