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Open Virtual Network

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What Open Virtual Network is

Open Virtual Network (OVN) provides logical networking for virtual machine and container environments, intended for use by cloud management software. It translates virtual network configurations into OpenFlow and models networks through logical routers and switches. Listed features include distributed virtual routers and switches, access control lists, DHCP, and a DNS server.

Logical networks use tunnels or other encapsulations to remain separate from physical and virtual networks, allowing address spaces to overlap. Virtual machines can migrate between physical machines without network disruption, and gateways connect tunnel-based logical networks to physical networks. The architecture names OpenStack Neutron’s ml2/ovn plugin and ovn-kubernetes as cloud management examples. OVN is free open-source software under the Apache 2 license, with an on-premises deployment model and a centralized control plane. It runs entirely in userspace, requires no kernel modules, and is written in platform-independent C. Its generic installation guide covers Linux, FreeBSD, and NetBSD hosts. OpenSSL libssl is optional but recommended for secure connections to OVN database servers.

Who it suits

OVN is intended for cloud management software and teams building logical networks for virtual machines or containers. Its documented host coverage includes Linux, FreeBSD, and NetBSD.

What it does well

  • Free open-source software under Apache 2
  • Provides logical routers and switches
  • Supports overlapping network address spaces
  • Runs in userspace without kernel modules
  • Virtual machines can migrate without network disruption

What to know first

  • Intended for use by cloud management software
  • OpenSSL libssl is optional but recommended for secure database connections

Plans

PlanBilled and limitsPrice
OVNOpen source Apache 2 licenseFree

As ovn.org lists them, read 5 Oct 2026. The maker's own page has the final word.

Getting started

  1. Visit the OVN website.
  2. Use the generic build and installation guide for a Linux, FreeBSD, or NetBSD host.
  3. Build and install OVN on premises.
  4. Connect it to cloud management software such as OpenStack Neutron’s ml2/ovn plugin or ovn-kubernetes.
  5. Consider OpenSSL libssl for secure connections between OVN services and OVN database servers.

Verdict

OVN provides logical network abstractions and related networking features for cloud management environments. Teams should account for its on-premises deployment model and the recommended transport-security setup.

Questions

Is Open Virtual Network free?

Yes. OVN is listed as free open-source software under the Apache 2 license.

Which operating systems does OVN support?

The listed platform is Linux and self-hosted. Its generic build and installation guide covers Linux, FreeBSD, and NetBSD hosts.

Can OVN connect logical networks to physical networks?

Yes. OVN provides gateways from tunnel-based logical networks to physical networks.

Which cloud management projects are named as examples?

The architecture page names OpenStack Neutron’s ml2/ovn plugin and the ovn-kubernetes project.

Does OVN require kernel modules?

No. It runs entirely in userspace and requires no kernel modules.

What transport protocols are supported?

The listed protocols are Geneve, VXLAN, OpenFlow, OVSDB, and IPsec.

Facts from Open Virtual Network's own pages

Architecture
OVN translates virtual network configurations into OpenFlow and provides a higher-level abstraction based on logical routers and switches. · ovn.org, 5 Oct 2026
Audience
OVN is intended to be used by cloud management software. · ovn.org, 5 Oct 2026
Features
Listed features include distributed virtual routers, distributed logical switches, access control lists, DHCP, and a DNS server. · ovn.org, 5 Oct 2026
Gateways
OVN provides gateways to connect tunnel-based logical networks to physical networks. · ovn.org, 5 Oct 2026
Integrations
The architecture page names OpenStack Neutron’s ml2/ovn plugin and the ovn-kubernetes project as cloud management system examples. · ovn.org, 5 Oct 2026
Mobility
Virtual machines in a logical network can migrate between physical machines without network disruption. · ovn.org, 5 Oct 2026
Overlays
OVN logical networks use tunnels or other encapsulations to isolate them from physical and virtual networks, allowing address spaces to overlap. · ovn.org, 5 Oct 2026
Purpose
OVN is a system that supports logical network abstraction in virtual machine and container environments. · ovn.org, 5 Oct 2026
Release support
Standard term releases receive full bug-fix support for one year after initial release; LTS releases receive bug-fix support for two years and another year of critical and security fixes after a new LTS is released. · ovn.org, 5 Oct 2026
Runtime
OVN is written in platform-independent C, runs entirely in userspace, and requires no kernel modules to be installed. · ovn.org, 5 Oct 2026
Security
OVN’s security process directs vulnerability reports to the ovs-security mailing list for coordinated handling. · docs.ovn.org, 5 Oct 2026
Support
The installation guide directs users to GitHub issues or [email protected] to report problems. · docs.ovn.org, 5 Oct 2026
Supported systems
The generic build and installation guide covers Linux, FreeBSD, and NetBSD hosts. · docs.ovn.org, 5 Oct 2026
Transport security
OpenSSL libssl is optional but recommended for securely connecting OVN services to OVN database servers. · docs.ovn.org, 5 Oct 2026

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