At Cisco Live! in London this week, Cisco is demonstrating some enhancements to its Nexus 1000V virtual switch that greatly ease some of the challenges in deploying VXLAN in large scale cloud networks. VXLAN was designed to solve the problem of setting up traditional virtual networks (VLANs) in large multi-tenant cloud environments: the limited ID range for VLAN tags was quickly exhausted and a larger ID pool was needed for larger shared infrastructures. VXLAN thus becomes the foundation for a virtual network tunnel or virtual network overlays on top of physical networks. And unlike VLANs, VXLANs are designed to act as L2 virtual networks over L3 physical networks. For a more in-depth refresher on VXLAN, start here.
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While VXLANs have certainly enabled a whole new level of scalability for virtual networks, one of the challenges in deploying VXLAN is its use of IP Multicast to implement the L2 over L3 network capability. Why is this? VXLAN is a MAC-in-IP encapsulation protocol in a UDP frame. The virtual switch that acts as the VXLAN termination (in Cisco’s case, the Nexus 1000V virtual switch) takes the L2 packet from the VM, wraps it in a L3 IP header, and sends it out over UDP. But the challenge is that there’s no way to determine which IP address should be used for the destination host (VXLAN termination point) at which the desired MAC address can be found. In other protocols, this can be accomplished within the network control plane and some MAC to IP mapping protocol, but the VXLAN specification indicates there should be no reliance on a control plane or a physical to virtual mapping table.
[Update 11/26/12: the free Nexus 1000V virtual switch is available for download from here.]
Following on the heels of the announcement of our Nexus 1000V 2.1 release last month, Cisco is today announcing a new pricing and packaging strategy for its flagship virtual switch portfolio. Starting with that new 2.1 release, which is now in beta, we will have two editions of the Nexus 1000V, an Essential Edition and an Advanced Edition. The Nexus 1000V Essential Edition will be available for free, plus a nominal annual support fee, in a move that we believe will encourage customers and our partners to proliferate what has already become the most popular virtual switch in the industry with over 6,000 customers to date.
The Nexus 1000V Essential Edition provides all the rich Layer-2 networking features to connect virtual applications to the network and integrate into VMware environments, including: VXLAN capability, Cisco vPath service insertion, integration with vCloud Director, and a plug-in for management and monitoring in VMware’s vCenter Server. This free version will enable rapid, low-risk adoption of Cisco’s virtual network technology environments.
The Advanced Edition, priced at $695 per CPU, the same price as the current 1.5 release, includes:
The Cisco Virtual Security Gateway (VSG) for Nexus 1000V, a virtual firewall with visibility to virtual machine attributes for building sophisticated compliance policies, and logical trust zones between applications (VSG was previously sold as a separate product).
The lack of programmability in existing networking hardware is certainly a problem, but VMware’s acquisition of Nicira does not mean that Cisco and its ilk will be marginalized… It does mean the role and management of the physical network is changing, and I think Cisco is further ahead than most of its competitors in creating a vision for the next phase of networking.
My take here was that the VMware-Nicira acquisition did not portend a strategic break with Cisco, and while there are some obvious overlaps in our product lines, there are still a number of areas of collaboration, cooperation and interoperability. The virtual network infrastructure is just one piece of a larger software stack and the differentiation will likely be decided in the orchestration, management and applications built on top of the newly programmable infrastructures sometime down the road. Read More »
Continuing on our theme of virtual network overlays and programmable networks, today we’ll look at how to increase workload mobility over more data center and cloud resources. If server virtualization increases resource utilization and reduces costs, and data center consolidation is a good thing, then it follows that the larger the resource pool that your virtual workloads can migrate over, the more cost effective your IT operation can be. And if your mobility diameter spans multiple sites, you can obviously improve your fault tolerance as well. We call this increasing your mobility diameter, and we’ll complement what we’ve already learned about VXLAN and virtual overlays with some new technologies to seamlessly scale your diameter up. (Sounds like some sort of bizarre reverse Weight Watchers program, doesn’t it?).
As we noted in our VXLAN overview, VXLANs enable private virtual overlays over layer 3 boundaries via their MAC in UDP encapsulation and the cool way they filter MAC address broadcasts to only the right subnets. However, when you are doing full on application migration over a layer 3 boundary, VXLAN alone isn’t going to do it alone. In order to extend virtual workload mobility beyond layer 2 boundaries, Cisco came up with Overlay Transport Virtualization (OTV) that can work in conjunction with VXLAN to extend application mobility to any point the VXLAN virtual overlay can reach. And not surprisingly, the media wizards over at TechWise TV have a great video that takes all the complexity of OTV and makes it cartoonishly simple.
At Cisco live last month I spent several days talking to a lot of customers about all the new enhancements to our Nexus 1000V portfolio, especially the programmable virtual network overlays that are part of the Cisco ONE framework for SDN/network programmability. While the Nexus 1000V-based virtual networks are really gaining traction (6,000+ Nexus 1000V virtual switch customers to date), I still found a lot of folks weren’t all that familiar with the concept of VXLAN, and why they are so important to building scalable cloud networks and multi-tenant data centers.
Well, not to fear, VXLAN MAN is here! Well, not really, but we have just released a great new fundamentals video on VXLAN from the creative geniuses at Techwise TV (Thanks to @JimmyRay_Purser and @robbboyd!). We’ve gotten great reviews on this so far, and I know the guys really had a fun time in creating this one.