- The Data Center LAN Evolution Series
- A Webtorials Thought Leadership Discussion
- Dr. Jim Metzler, Moderator
- Featuring Arista, Avaya, Brocade, Cisco Systems, Extreme Networks and HP
There is no doubt that over the last couple of years that the topic of virtualization has received considerable attention in the trade press. Virtualization, however, is more than a media event. For example our research indicates that over 90% of IT organizations have implemented at least some server virtualization and that in the coming year most IT organizations will increase the percentage of their servers that are virtualized. In addition to being more than a media event, the topic of virtualization is bigger than just server virtualization. Today, almost every component of IT can and is being virtualized.
This month's discussion will focus on virtualization. As in the previous discussions, we will start with a fairly high level question and then ask more granular questions over the month. In order to make this discussion somewhat interactive, kindly feel free to send us questions or comments.
- Related discussion: What's the Best Alternative to Spanning Tree?
- Related Discussion: Does Converging the LAN and SAN Make Sense?
- Related Discussion: Does OpenFlow Make Sense in Enterprise Networks?
In order to comment on the discussion here and/or to suggest further questions, please send email to Jim Metzler or simply enter your comment into the form below.
Virtualization broadly defined is a hot topic for virtually all IT organizations. What impact does virtualization have on data center LAN switching?
Virtualization within the Data Center is now taken for granted, with some declaring that ‘Cloud Computing’ will be the choice of most enterprises and that applications and information will become commodities. Experience has proved one thing; the Data Center of the future cannot be built on the technology of the past. General-purpose products, outmoded techniques, and legacy designs cannot be re-packaged as ‘Data Center-ready’. The industry will take the best and leave the rest. Ethernet is readily available, cost-effective, extensible, and – as the 40/100 Gigabit developments prove – scalable, however many existing deployment methodologies are no longer an option.
The benefits implied by large-scale application and server virtualization – higher efficiency levels, faster time-to-service, reduced hardware costs, smaller footprint – set an expectation that create new challenges for the underlying network. Traditional networks were conceived in a time before the demands of a high-virtualized compute environment.
Specifically, the next-generation Data Center network needs to empower:
• Virtual Machine connectivity optimization and life cycle migration – virtualized servers are operationalised very quickly and very dynamically; the network must react quickly and seamlessly
• Effective segmentation of traffic by application – a myriad of business and operational drivers mandate the support for a series of full-featured virtualized networks; much is Layer 2-only but Layer 3 functionality is also key
• Efficient service provisioning and orchestration – time-to-service demands dictate that the network dynamically and automatically responds to service changes; innovations can negate the change administration burden and change-induced errors
Provisioning needs to be simpler, and availability and performance need to scale seamlessly. Empowering a truly commoditized approach to service delivery requires a solution that is characterized by simplification, and a standards-based approach will help ensure an open architecture that avoids costly or inflexible lock-in.
There are many degrees to which a switch is virtualized, defined by the level of fault containment and management separation provided. The main elements that characterize the degree to which a network switch is virtualized include:
Control plane: The capability to create multiple independent instances of the control plane elements enables the creation of multiple logical topologies and fault domains
Data (or forwarding) plane: Forwarding tables and other databases can be partitioned to provide data segregation.
Management plane: Well-delineated management environments can be provided independently for each virtual device.
Software partitioning: Modular software processes can be grouped in partitions that are dedicated to specific virtual devices, thus creating well-defined fault domains.
Hardware components: Hardware components can be partitioned and dedicated to specific virtual devices, allowing predictable allocation of hardware resources to different virtual devices.
The Cisco Switches supports all these degrees of virtualization. The Cisco innovation, through virtual device contexts (VDCs), which allows the switches to be virtualized at the device level by separating logical entity within the switch, maintaining its own unique set of running software processes, having its own configuration, and being managed by a separate administrator.
IMPACT: The capability to consolidate multiple functions onto fewer devices leads to a simplified architecture, which provides operating efficiencies by reducing the number of tasks to be processed as well as the number of elements to be maintained without sacrificing efficiency, utilization, and scalability. VDCs improve CapEx/OpEx by optimizing power consumption, space requirements, device utilization, maintenance operations, and ultimately, service speed
Virtualization has a significant impact on switching because it impacts the network in many ways. From the technology perspective, virtualization consolidates the network and increases performance requirements. Virtualization increases the load coming from servers, meaning the need becomes acute for highly dense, wire-speed L2/3 switching of 10/40GbE. The design of data center networks flatten out to support east-west traffic flows, and very importantly, to reduce hops and latency.
Most important is the human side: Server virtualization brings with it a set of operational challenges from dealing with configuration challenges around Virtual Machine (VM) switching to managing virtual machine mobility in the network, to providing virtual machine location and inventory in the network. Today, there are only a few tools available to the network administrator that provides visibility, control and insight into the virtual machine environment. This white paper outlines the problem well.
Widespread deployment of high-density, highly virtualized, federated applications will require much larger-scale, lower-latency, flatter, layer 2-oriented network architectures to support server-to-server traffic and vMotion/Live Migration-driven virtual server migration
These high-density deployments will push much higher server hardware utilization rates and drive demand for new network architectures that provide higher speed server access connections and larger-scale core/interconnect capacity.
These network architectures will be built on higher performance platforms and employ new networking tools that displace legacy Spanning Tree and Virtual Router Redundancy protocols to deliver much higher network performance and link utilization while significantly improving network availability and simplifying network management.
Building upon and complementing existing innovative tools like HP’s Intelligent Resilient Framework, a new set of standards-based, layer 2-focused multi-pathing technologies like TRILL and SPB will further empower customers to deploy more scalable, more highly-available, flatter network architectures that propel server virtualization.
IRF is an innovative HP switch platform virtualization technology that allows customers to dramatically simplify the design and operations of their data center and campus Ethernet networks.
HP IRF overcomes comes the limitations of traditional Spanning Tree Protocol (STP) based and legacy competitive designs by delivering new levels of network performance and resiliency.