The Citrix Open vSwitch appears online

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In May, during its main conference Synergy, Citrix announced the existence of an open source virtual switch that may compete with the Nexus 1000V that Cisco made available for VMware vSphere.

In early June, the Citrix CTO Simon Crosby shared a very few details about it, but so far most of the virtualization community doesn’t know much about it. But the official website about the project quietly appeared online now: the product is called Open vSwitch and is released under the Apache 2 open source license.

The first release (which is almost complete and available online as well) is designed to support distributed networking (like the Cisco Nexus 1000V) and includes the following features:

  • Visibility into inter-VM communication via NetFlow, SPAN, and RSPAN
  • Standard 802.1Q VLAN model with trunking
  • Per VM policing
  • NIC bonding with source-MAC load balancing
  • Kernel-based forwarding
  • Support for OpenFlow
  • Compatibility layer for the Linux bridging code
    (The Open vSwitch can be even used inside a plain Linux distribution in place of operating system bridge)


On top of that the following features are part of the roadmap:

  • User-space forwarding engine
  • sFlow
  • Compatibility layer for VDE
  • Ethernet over GRE (for ERSPAN and virtual private network creation)
  • Full L3 support + NAT
  • Priority-based QoS
  • More management interfaces (IOS-like CLI, SNMP, NetFlow)
  • 802.1x/RADIUS
  • Support for hardware acceleration (VMDQ, switching chips on SR-IOV NICs)

The version available online is near the 1.0 (0.90.4), but it’s only available as source code.
The online documentation already explains how to use it with a XenServer 5.5 host.