Open vSwitch for Windows (dbosoft)

What is this fork?

This repository is dbosoft's Windows-focused fork of Open vSwitch. It is not an official Open vSwitch release and is not affiliated with or endorsed by the upstream Open vSwitch project.

Upstream Open vSwitch deprecated Windows support in v3.7 and removed it from the main branch entirely. This fork re-establishes and continues development of:

• the ovsext NDIS forwarding extension (the Windows kernel datapath), and
• the Windows userspace components (ovs-vswitchd, ovsdb-server, and the ovs-* tools) together with a native, MSYS-free CMake build.

The fork is based on upstream Open vSwitch main (after the Windows removal) and is periodically resynced with upstream. All non-Windows platforms (Linux, FreeBSD, DPDK, userspace datapath) continue to inherit upstream behaviour unchanged; our additions are Windows-specific. See NEWS_WINDOWS for the changes that are unique to this fork on top of the upstream baseline tracked in NEWS.

If you are running Open vSwitch on Linux, FreeBSD, or with DPDK, you almost certainly want the upstream project at https://github.com/openvswitch/ovs instead of this fork.

What is Open vSwitch?

Open vSwitch is a multilayer software switch licensed under the open source Apache 2 license. Its goal is to implement a production quality switch platform that supports standard management interfaces and opens the forwarding functions to programmatic extension and control.

On Windows, Open vSwitch integrates with Hyper-V as an NDIS forwarding extension on the virtual switch, providing flow-based forwarding for virtual machine traffic. Open vSwitch supports, among other features:

• Standard 802.1Q VLAN model with trunk and access ports
• NIC bonding with or without LACP on the upstream switch
• NetFlow, sFlow(R), and mirroring for increased visibility
• QoS (Quality of Service) configuration, plus policing
• Geneve, GRE, VXLAN, ERSPAN, GTP-U, SRv6, and Bareudp tunneling
• OpenFlow 1.0 plus numerous extensions
• Transactional configuration database with C and Python bindings

Two READMEs? The upstream README.rst is left untouched to keep this fork's divergence from upstream minimal. This Windows-specific README.md is added alongside it.

What's here?

The main components of this distribution are:

• ovsext, the Windows NDIS forwarding extension implementing the kernel datapath, under datapath-windows/.
• ovs-vswitchd, a daemon that implements the switch.
• ovsdb-server, a lightweight database server that ovs-vswitchd queries to obtain its configuration.
• ovs-vsctl, a utility for querying and updating the configuration of ovs-vswitchd.
• ovs-appctl, a utility that sends commands to running Open vSwitch daemons.
• ovs-dpctl, a tool for configuring the switch datapath.

Open vSwitch also provides some tools:

• ovs-ofctl, a utility for querying and controlling OpenFlow switches and controllers.
• ovs-pki, a utility for creating and managing the public-key infrastructure for OpenFlow switches.
• ovs-testcontroller, a simple OpenFlow controller that may be useful for testing (though not for production).

Building on Windows

The Windows build uses CMake with Visual Studio 2022 (no MSYS/autotools). The ovsext driver is built with the Windows Driver Kit (WDK). The Build for Windows (CMake) GitHub Actions workflow shows the canonical build and test steps.

For background on Open vSwitch concepts, the upstream documentation under Documentation/ remains a useful reference. Note: that documentation is inherited from upstream and is not maintained for this Windows fork — it may describe Linux-specific procedures or features that do not apply here, and may be stale with respect to the Windows port.

License

Open vSwitch is licensed under the open source Apache 2 license. Some files may be marked specifically with a different license, in which case that license applies to the file in question.

• Files under the datapath directory are licensed under the GNU General Public License, version 2.
• lib/conntrack-tcp.c is licensed under the 2-clause BSD license.
• lib/sflow*.[ch] are licensed under the terms of either the Sun Industry Standards Source License 1.1 (http://host-sflow.sourceforge.net/sissl.html) or the InMon sFlow License (http://www.inmon.com/technology/sflowlicense.txt).

Contact

For issues specific to this Windows fork, please use the issue tracker at https://github.com/dbosoft/ovs/issues.

Upstream Open vSwitch can be reached at [email protected].