Linux Virtual Server vs PureLB

Linux Virtual Server (LVS) turns a cluster of real Linux servers into one virtual server for users. Its IPVS component performs layer 4 balancing in the Linux kernel, directing TCP and UDP requests sent to a virtual service IP toward servers behind it. Supported forwarding methods are NAT, FULLNAT, tunneling, and direct routing. The project lists web, cache, mail, FTP, media, and VoIP services as applications. Capacity can be changed by adding or removing cluster nodes. Failure detection can identify node or daemon problems and reconfigure the system for availability. Keepalived checks server-pool state at layers 3, 4, and 5 and tells the kernel to remove a failed server. KTCPVS supplies application-level balancing but is under development. LVS is free GPL-licensed software for Linux and self-hosted use. Administration uses ipvsadm, with documentation for configurations, scheduling, high availability, and DoS defense.

PureLB is a Kubernetes Service LoadBalancer for bare-metal Linux clusters. It allocates external IP addresses from configured pools and announces them through Linux networking, with optional BGP for remote addresses. ServiceGroups use exactly one pool type: local, remote, or Netbox. Local addresses are attached to host interfaces, and a Kubernetes Lease election chooses which node announces each address; another node can take over if that node fails. Remote addresses are placed on a dummy interface on every node and advertised through BGP, allowing an upstream router to distribute traffic with ECMP. Pools can contain IPv4, IPv6, or both for dual-stack deployments. Kubernetes Custom Resource Definitions configure pools and node agents. Installation uses kubectl manifests or Helm, with Helm recommended for production. PureLB requires a Kubernetes cluster with an operational CNI and Linux nodes. It is free, open source, Apache 2.0 licensed, and self-hosted. Prometheus metrics are exposed on port 7472 at /metrics. NetBox integration is documented but currently unsupported and may not work with recent versions.