MetalLB vs OpenELB

MetalLB provides network load balancing for Kubernetes clusters that do not run on a cloud provider. It assigns service IP addresses from operator-configured pools and announces them through ARP, NDP, or BGP, depending on the chosen mode. In layer 2 mode, one cluster machine announces an address using ARP for IPv4 or NDP for IPv6. In BGP mode, cluster machines peer with nearby routers, which can distribute traffic across multiple nodes. The recommended FRR-K8s mode supports BFD, IPv6, and merging additional FRR configuration. MetalLB is open source, with no paid plans listed. Installation options include Kubernetes manifests, Kustomize, Helm, and an Operator on OperatorHub. After installation it remains idle until configured with resources such as an IPAddressPool in its deployment namespace. Requirements include Kubernetes 1.13.0 or later, a compatible cluster network, and IPv4 addresses. The project lists AWS, Azure, DigitalOcean, and Google Cloud as unsupported and says it is generally incompatible with cloud providers. MetalLB describes itself as a beta project and cautions that its configuration format may change incompatibly as development continues.

OpenELB exposes Kubernetes LoadBalancer services externally in bare-metal, edge, and virtualization environments. It assigns service addresses from Eip-managed IP pools and supports BGP, Layer 2, and VIP load-balancing modes. BGP mode uses GoBGP to publish routes to peer routers and supports ECMP, while BgpConf and BgpPeer custom resources configure BGP properties. Layer 2 mode requires infrastructure that permits anonymous ARP/NDP packets. VIP mode uses VRRP for high availability. OpenELB can be installed with kubectl manifests or Helm 3 in Kubernetes 1.15 or later, and guides are listed for Kubernetes, K3s, and KubeSphere. The project currently supports IPv4 only and is not a managed service. Layer 2 and VIP modes forward through one active node, so failover can briefly interrupt services and bandwidth is limited by that node. BGP requires a router supporting BGP and ECMP. OpenELB uses Apache License 2.0.