Multilayer Virtual Switch

Simon Crosby already talked about it, and it is already here. Open Source Routing’s powerful counterpart, Open Source Switching is available now. Open vSwitch is a multilayer virtual switch licensed under the open source Apache 2.0 license. The goal is to build a production quality switch for VM environments that supports standard management interfaces (e.g. NetFlow, RSPAN, ERSPAN, CLI), and is open to programmatic extension and control. In addition, it is designed to support distribution across multiple physical servers similar to VMware’s vNetwork distributed vswitch or Cisco’s Nexus 1000V.

Open vSwitch currently supports multiple virtualization technologies. It is the default switch in the Xen Cloud Platform and also supports Xen, XenServer, KVM, and VirtualBox. The bulk of the code is written in platform-independent C and is easily ported to other environments.

To understand why virtualized environments require a new approach to switching, read the WHY-OVS document that is distributed with the source code.

Supported Features:

  • Visibility into inter-VM communication via NetFlow, sFlow(R), SPAN, and RSPAN
  • Standard 802.1Q VLAN model with trunking
  • Fine-grained min/max rate QoS
  • Per VM interface traffic policing
  • NIC bonding with source-MAC load balancing
  • OpenFlow Protocol Support
  • Ethernet over GRE tunneling
  • Compatibility layer for the Linux bridging code
  • Kernel and user-space forwarding engine options


  • L3 switching
  • IPsec tunneling
  • LACP
  • LLDP / CDP
  • Support for hardware acceleration (VMDQ, switching chips on SR-IOV NICs)
  • Improved management interfaces (CLI, SNMP, NETCONF)

Read more here

It’s powerful!