The Hetzner Cloud network stack - history and technical overview
Summary
Hetzner describes the evolution of its cloud network stack, focusing on a host-centric approach with Open vSwitch, a custom Flusskrebs controller, and VXLAN-based private networks. The article documents the historical shift from NAT-based networking and direct IPv4 routing to Open vSwitch data planes and private cloud networks, including BGP uplinks. It emphasizes owning the network stack to improve reliability, scalability, and operational flexibility, and teases future upgrades in the series.