Open vSwitch

Open vSwitch is a production quality, multilayer virtual switch licensed under the open source Apache 2.0 licence. It is one of the foundational components of software defined networking, providing the switching layer inside hypervisors and hosts where virtual machines and containers connect to the network.

Multilayer means it operates across several layers of the network stack rather than switching frames alone, which is what allows a virtual switch to enforce policy, tunnel traffic and support the overlay networks that virtualised infrastructure depends on. Many higher level SDN platforms use it as their data plane rather than implementing their own, which is why it appears beneath products that never mention it.

Being production quality is the claim that matters most in this position. A virtual switch sits in the path of every packet a host sends or receives, so a defect is not a degraded feature but an outage. Open vSwitch has been deployed at scale in cloud and telecommunications infrastructure for many years.

The project sustains an active technical community, running the OVS and OVN conference series annually since 2016, alongside a further presence at events such as OpenStack Boston. Documentation, manual pages and recorded talks and presentations are published, and the Apache 2.0 licence permits commercial use without a licence fee.