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Of all of the features of the Nexus 7000 series switch, there are few that have attracted more attention than Overlay Transport Virtualisation (OTV). This is the name of a datacentre connectivity solution that allows for the reliable and safe spanning of Layer two networks across more than one site. There are other, more traditional methods of spanning Virtual Local Area Networks (VLANs) across sites, which include MPLS or L2TP tunnels, but they also have costs, risks and other downsides that many people would rather avoid. That’s why you may be interested in the different approach of OTV, and by getting in touch with the experts at Proxar IT Consulting, you can have an OTV enabled multi-centre strategy successfully designed and implemented.

Advantages of virtualisation

There are still no signs of the dependency of companies on data relenting any time soon, and it has become increasingly the norm to store, process and exchange this data on compute platforms in datacentres. Over time, datacentres are becoming more critical than ever. One inexorable trend in datacentre management is the growth of virtualisation, which was previously the preserve of high-end mainframe and Unix platforms. Today, VMWare and other vendors have brought the flexibility and availability of virtualised compute power to the industry standard (x86) server space.

One key benefit of heavily virtualised workloads is the ability to move operating system workloads dynamically from host to host, across racks or even across datacentres. This could be in response to shifting demands, disaster events or even such opportunities as that to reduce power/cooling costs in one centre over another. Wide area distributed clustering puts similar demands on networks. However, it is to facilitate the seamless movement of workloads that layer 2 (broadcast) Ethernet networks need to be available across centres. Ensuring this, however, poses a number of challenges.

Virtualisation Solutions

Although the simplest solution is to commission dark fibre and deploy Ethernet across datacentres, this is prohibitively costly for most enterprises unless the datacentres are closely located, and all broadcast traffic at both locations will be re-transmitted across the link. A broadcast storm at one location could take down networks at every datacentre that is connected in this way.

More complex solutions exist, such as those that involve layer two tunnelling over layer three networks in the manner of L2TP, and these scale well over distance where dedicated fibre is not feasible. However, these solutions come at the cost of greater complexity, with the danger still present of a one site disaster spreading to all connected datacentres.

How Overlay Transport Virtualisation works

It is in order to resolve these issues and provide support for the seamless interconnection of layer two domains that Cisco has introduced a new technology, known as Cisco Overlay Transport Virtualisation (or OTV). Cisco OTV is a method that allows for the easy and transparent connection of Layer two Ethernet over other IP WAN networks, in order to create a merged, single, logical datacentre network.

OTV is a routing system for Layer 2 MAC addresses that enables a suitable datacentre router – a feature that is presently exclusive to the Cisco Nexus 7000 – to encapsulate a MAC address in an IP packet and route to the correct destination datacentre. There is no broadcast of MAC addresses between the datacentres, while suppression technologies are also incorporated in order to prevent a broadcast storm or spanning tree loop at one datacentre affecting an adjacent one.

Contact Proxar about OTV

OTV drastically simplifies not only the management of datacentres that share virtualised or clustered workloads, but also the process of adding new datacentres to a network. By placing a Cisco Nexus 7000 at the edge and issuing a handful of commands at the new datacentre site, all configured layer two domains can be made seamlessly available, with no configuration at existing sites required.

Proxar IT Consulting is able to plan, design, specify and deploy OTV on Nexus 7000 series switches. Even where non-Cisco equipment is in use, OTV can be run between suitable switches without the fear that intervening devices will prevent the protocols from working properly – provided that they forward layer 3 packets correctly. Proxar IT Consulting can help you to upgrade existing networks so that you can enjoy the benefits of Nexus OTV without a rip-and-replace of all existing network hardware.

Overlay Transport Virtualisation Services London, UK – Proxar IT Consulting