Open vSwitch, sometimes abbreviated as OVS, is an open-source implementation of a distributed virtualmultilayer switch. The main purpose of Open vSwitch is to provide a switching stack for hardware virtualization environments, while supporting multiple protocols and standards used in computer networks. The project's source code is distributed under the terms of Apache License 2.0.
Overview
Open vSwitch is a software implementation of a virtual multilayer network switch, designed to enable effective network automation through programmatic extensions, while supporting standard management interfaces and protocols such as NetFlow, sFlow, SPAN, RSPAN, CLI, LACP and 802.1ag. In addition, Open vSwitch is designed to support transparent distribution across multiple physical servers by enabling creation of cross-server switches in a way that abstracts out the underlying server architecture, similar to the VMware vNetwork distributed vswitch or CiscoNexus 1000V. Open vSwitch can operate both as a software-based network switch running within a virtual machinehypervisor, and as the control stack for dedicated switching hardware; as a result, it has been ported to multiple virtualization platforms, switching chipsets, and networking hardware accelerators. Open vSwitch is the default network switch in the XenServer virtualization platform since its version 6.0, and in the Xen Cloud Platform via its XAPI management toolstack. It also supports Xen, Linux KVM, Proxmox VE and VirtualBox hypervisors, while a port to Hyper-V is also available. Open vSwitch has also been integrated into various cloud computing software platforms and virtualization management systems, including OpenStack, openQRM, OpenNebula and oVirt. The Linux kernel implementation of Open vSwitch was merged into the kernel mainline in kernel version 3.3, which was released on March 18, 2012; official Linux packages are available for Debian, Fedora, openSUSE and Ubuntu. , FreeBSD and NetBSD implementations are also available, with the NetBSD's implementation operating completely in userspace. The majority of the Open vSwitch source code is written in platform-independent C language, which provides easy portability to various environments. The source code is licensed under the Apache License 2.0.
Features
, features provided by Open vSwitch include the following:
Implementation of the packet forwarding engine in kernel space or userspace, allowing additional flexibility as well as providing performance improvements by processing the majority of forwarded packets without leaving the kernel space and by using multithreaded kernel space and userspace components
Multi-table forwarding pipeline with a flow-caching engine
Forwarding layer abstraction, making it easier to port Open vSwitch to new software and hardware platforms
