vNetworks: Software VLANs without Borders
Virtual local area networks (VLANs) were invented over 20 years ago, and thus far have given IT a significant capability in segmenting networks and traffic, allowing networks to run faster and more efficiently. However, the advent of cloud computing, both public and private, along with cloud bursting, has broken the traditional network and made network management more complex. What’s needed is a platform-agnostic VLAN that can span across geographic and logical limits to rein in the infrastructure your workloads can sit on. This research note will focus on emerging network virtualization solutions that promise to give you a unified view of your network and servers.
Oh Where, Oh Where Has My Server Gone?
VLANs were first introduced to the networking world in 1988. They have a come a long way since then, with major revisions as recently as 2007. VLANs are not a perfect solution though, as you cannot extend them beyond the private, corporate network. They are limited to physically connected networks, making them unsuitable for today’s shifting IT environment.
Cloud computing has broken the traditional network boundaries, and so a new solution is needed. VMware and Cisco have a proprietary solution that uses Cisco’s Nexus 1000V virtual switch integrated with vSphere, but this solution doesn’t integrate with hypervisors from other vendors.
Instead, network virtualization gives you the ability to create VLANs across geographically and logically disparate networks. Each virtual network (vNetwork) can be isolated and managed separately from other vNetworks, giving IT the power to create vNetworks based on applications that extend from on-premise infrastructure to public cloud infrastructure.
Any node, in any location, can be registered as part of a vNetwork, whether it’s a physical server, virtual server, on-premise, or in a public Infrastructure-as-a-Service (IaaS) cloud. Each node receives virtual MAC and IP addresses unique to the vNetwork, allowing data to flow solely through the vNetwork.
This is different from a VLAN, which traditionally required configuring ports on your physical switch to make the connected device part of the VLAN. vNetwork switches are pure software implementations of network switches, providing more flexibility over the configuration of the network, with the ability to bring nodes from public IaaS clouds (e.g. Amazon EC2) and servers rented from hosting providers (e.g. Rackspace) all into a single vNetwork.
vNetworks Sound Great on Paper
If you have a network at all resembling the examples shown on vCider’s website (a startup in the network virtualization space), vNetworks will provide at least two key benefits to network management:
- Flexibility. Organizations are looking to optimize costs and operational efficiency by moving workloads to the least expensive platform and to improve service availability by building application delivery networks and high availability configurations. vNetwork software makes this possible.
- Platform agnosticism. Existing solutions from Cisco and VMware are proprietary and only work in Cisco networks supporting VMware environments. However, a new breed of vNetwork solutions from vCider, and soon-to-be-launched products from Nicira and Big Switch Networks, will provide you with the ability to manage virtual machines running on multiple hypervisors or cloud servers from multiple providers, all on a network that could be built on HP, Dell, Cisco, and Aruba networking gear.
We’re just at the Beginning
At the moment, these solutions are working at layer 3 (the network layer) of the OSI stack. That is a good and natural place to be, given the path selection and internetworking capabilities embedded at that layer. Ideally, virtual switches would also operate at layer 4, providing great control over TCP and UDP connections, fostering end-to-end connectivity as well.
In the meantime, vCider, Nicira, and Big Switch are all very young companies with, for the most part, unproven solutions. Only vCider’s solution has launched and is commercially available, though both vCider and Big Switch showcased their products at GigaOM Structure 2011.
Initially, these products will support the most well-known cloud IaaS and networking vendors – Amazon, Rackspace, Cisco – and then move to other vendors with less market share. If you didn’t jump on the Amazon and Rackspace bandwagon, instead waiting for a cloud IaaS provider that would better suit your needs, you’ll have to wait a bit longer for a vNetwork solution.
- Network virtualization will solve problems to do with cloud bursting, workload optimization, and connecting applications running on disparate networks. This will make it easier for businesses to manage those applications, regardless of where the instance is running.
- Paired with cloud orchestration and automation software, vNetworks put us one step closer to being able to dynamically, and automatically, shift workloads from one infrastructure to another while being able to maintain a persistent network configuration.
Virtual networks, or vNetworks, are coming on the scene to solve the problem of managing public cloud servers as a disparate network. When you can wrap your public cloud servers, rented dedicated servers, and on-premise servers into a single vNetwork, the promise of workload optimization and dynamic reallocation gets one step closer to reality.