Open vSwitch supports multiple hypervisors and the Xen Cloud Platform and competes with Cisco Nexus 1000V Credit: Gorodenkoff / Shutterstock When we talk about server virtualization, we often mention the resources behind the technology, such as the memory, CPU, and disk. We do so because at least one of these resources will ultimately become the bottleneck somewhere down the road on our path to consolidation. But what about the network? Remember the network — that thing that everyone used to point the finger at and assign blame to when something went wrong in the data center? The network is another virtualization resource, but one that doesn’t get nearly as much attention as the other three. [ Citrix XenServer 5.6 adds powerful new enterprise-grade features for data centers and cloud providers, as well as a new edition at a midrange price ] For the longest time, virtual networking wasn’t necessarily top of mind for virtualization administrators. In the dark ages of virtualization, they only had to deal with a simple virtualized network adapter. At the time, providing a virtual NIC seemed to be quite enough for basic virtualization deployments. Soon after, the platform vendors threw a rather simple proprietary switch into the mix but with very little sizzle and not much of a cool factor to it. For a while, that was pretty much the status quo and, for the most part, acceptable. By 2009, we had reached the age of enlightenment in the virtual world. Server virtualization platforms had matured, and virtualization administrators began architecting and deploying more complicated solutions and environments. Because of that, more virtual networking control became required. This was also the period when Cisco got into the game with the company’s first entry into the virtual switch market, the Nexus 1000V. It was a virtual machine access switch, and an intelligent software switch implementation for VMware vSphere environments running the Cisco NX-OS Software operating system. The interesting thing here was that if your physical data center was operating on Cisco gear, the Nexus 1000V provided a consistent networking feature set and provisioning process all the way from the virtual machine access layer to the core of the data center network infrastructure. This was a big deal, and it brought the sexy back to virtual networking and helped put the resource back on the virtual map. But Cisco wouldn’t be alone on this virtual switch quest for very long. The company had to know that something as useful as the Nexus 1000V wouldn’t be without competition for any extended period of time — it wasn’t. Shortly on the heels of the 1000V release, a new project was launched but with little fanfare; it was called the Open vSwitch Project. At the time of its launch, there was very little insight into exactly who was behind the project. Although there still aren’t any company names blasted on the project’s Website, it looks as though there may be involvement by Nicira (the virtualized networking startup with financial backing from ex-VMware CEO Diane Greene) and possibly Citrix. The Open vSwitch is described as a multilayer virtual switch licensed under the open source Apache 2 license. It is designed to support distribution across multiple physical servers similar to VMware’s distributed vSwitch or Cisco’s Nexus 1000V. The project’s stated goal is “to build a production quality switch for VM environments that supports standard management interfaces (e.g. NetFlow, RSPAN, ERSPAN, IOS-like CLI), and is open to programmatic extension and control.” What’s interesting about an open source virtual switch is that it could be the answer for a number of hardware OEMs who want to provide their own feature-rich virtual switch for use in their own products. This could also be a way for Cisco competitors to go after the network giant collectively, rather than attempting to go at them individually with their own offerings. Like other virtualization technologies, an open source virtual switch such as this would also abstract away the underlying hardware and provide organizations with a way to avoid vendor lock-in. In addition to being an open source technology, the Open vSwitch also differentiates itself by supporting multiple virtualization technologies. It is the default vSwitch in the latest Xen Cloud Platform (a complete cloud infrastructure platform with a powerful management stack based on open, standards-based APIs). It also supports open source Xen, XenServer, KVM, and VirtualBox virtualization hypervisors. The bulk of the code is written in platform-independent C, and is therefore easily ported to other environments. In a short period of time, the group has made a lot of progress. It was just over a week ago that the Open vSwitch project announced a 1.0.0 release with support for the following new features and enhancements: Visibility into inter-virtual machine communication via NetFlow, sFlow(R), SPAN, and RSPAN Standard 802.1Q VLAN model with trunking Per-virtual machine policing NIC bonding with source-MAC load balancing Support for OpenFlow Ethernet over GRE Compatibility layer for the Linux bridging code Kernel and user-space forwarding engine options Looking ahead, the group has a few other tricks up its sleeve for the virtual switch. As part of the road map, other ideas being tossed around include: Full L3 support (with NAT) More management interfaces (IOS-like CLI, SNMP, NETCONF) 802.1x/RADIUS Support for hardware acceleration (VMDQ, switching chips on SR-IOV NICs) If things continue to progress and advance in this way, the media might have to eventually start talking about network virtualization much the same way it talks about storage, desktop, or server virtualization today. Network virtualization will no longer have to live in the shadows, ashamed. For more information, check out the Open vSwitch project. Technology Industry