This week at Citrix Synergy, Citrix has quietly gone about discussing its forthcoming open source virtual switch for Xen and KVM hypervisors, which was mentioned during Wes Wasson’s day 2 keynote. Citrix may not have gone out of its way to issue a press release, but to me, it’s one of the most significant events at Synergy. Scott Lowe (via Twitter) feels the same way.

Cisco had to know that it was only a matter of time before competition for the Nexus 1000V started to emerge, and it appears that a virtual switch that competes with the Nexus 1000V will come right on the heels of the 1000V release. There’s no question that we’ve needed better virtual infrastructure switch management, and an overwhelming number of Burton Group clients are very interested in this technology. Client interest has generally been driven by two factors:

• Fully managed virtual switches would allow the organization’s networking group to regain control of the network infrastructure. Most network administrators have never been thrilled with having server administrators manage virtual switches.
• Managed virtual switches provide more granular insight into virtual network traffic and better integration with the organization’s existing network and security management tools

For awhile I’ve held the belief that the traditional network access layer was going to move to the virtual infrastructure. A large number of physical network and security appliance vendors believe that too, and are building or currently offering products that can be deployed directly to the virtual infrastructure. So for Cisco, the Nexus 1000V was important because it a) gave its clients functionality they desperately craved, but also b) protected existing revenue streams associated with network access layer devices. Throw in an open source managed virtual switch, and it could be problematic for Cisco’s continued dominance of the network market. Sure, Cisco’s competitors can’t go at Cisco individually, but by collectively rallying around an open source managed virtual switch, they have a chance. In my opinion, it won’t be long before the Xen virtual switch can be run via software on the hypervisor and will run on firmware on SR-IOV-enabled network interfaces or converged network adapters (CNAs).

I’m expecting Citrix to offer more details of the open source Xen virtual switch in the near future, but in the mean time, here’s what I can tell you:

• The virtual switch will be open source and initially compatible with both Xen- and KVM-based hypervisors
• It will provide centralized network management
• It will support advanced network management features such as Netflow, SPAN, RSPAN, and ERSPAN
• It will initially be available as a plug-in to XenCenter
• It will support security features such as ACLs and 802.1x

This is clearly a great move by Citrix. An open source virtual switch will allow a number of hardware OEMs to ship a robust virtual switch on their products, while also giving them the opportunity to add value to both their hardware devices (e.g., network adapters) and software management suites. Furthermore, an open source virtual switch that is shared by a large vendor community will enable organizations to deploy this virtual switch technology while avoiding vendor lock-in.

Citrix needed an answer to the Nexus 1000V and the advanced security inspection offered by VMsafe, and there’s no doubt they are on the right track with this announcement.