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Virtual switching with Open vSwitch

Switching Station

By Ralf Spenneberg

Virtualization with VMware, KVM, and Xen is here to stay. But up to now, no virtual switch has supported complex scenarios. Open vSwitch supports flows, VLANs, trunking, and port aggregation just like major league switches.

Many corporations are moving their infrastructure to virtual systems. This process involves virtualizing centralized components like SAP systems, Oracle database servers, email systems, and file servers, thus facilitating administration. Additionally, administrators no longer need to shut down systems for maintenance, because the workloads can be migrated on the fly to other virtual hosts.

One big disadvantage of a virtual environment has always been the simplistic network structure. Although physical network switches support VLANs, trunking, QoS, port aggregation, firewalling, and so on, virtual switches are very simple affairs. VMware and Cisco, however, provided a solution in the virtual Cisco Nexus 1000V switch. This switch integrates with the VMware environment and offers advanced functionality.

An open source product of this caliber previously has not been available, but Open vSwitch tackles the problem. Open vSwitch supports Xen, KVM, and VirtualBox, as well as XenServer. The next generation of Citrix will also be moving to Open vSwitch.

Open vSwitch [1], which is based on Stanford University's OpenFlow project [2], is a new open standard designed to support the management of switches and routers with arbitrary software (see the "OpenFlow" box).Open vSwitch gives the administrator the following features on a Linux system: