. http://blog.midokura.com/2016/01/architects-view-network-virtualization/
blog article
There has been a dramatic shift in networking – landscapes have changed and workloads are no longer stationary on physical servers. Dynamic workloads are now in containers or Virtual Machines, moving between inter and intra site locations. The introduction of virtualization removed the certainty of server and corresponding workload locations. As a result, network designs must adapt to the new style of workload fluidity. This type of elasticity puts pressure on traditional networks as it changes where the state and intelligence are positioned. Network state and rate of change are key elements affecting network performance and efficiency. To support new workload requirements, the network must become elastic and have the ability to dynamically follow workloads around the infrastructure. To accomplish this, a network overlay model exists consisting of a physical underlay and logical overlay. The physical underlay is the traditional physical network – its only concern is with IP endpoint reachability and doesn’t get involved with endpoint policies. It may take the form of a traditional Core, Aggregation and Access or a Leaf and Spine. The overlay is the software part and rides on top of the physical infrastructure. The overlay is software based and combined with a distributed architecture, maps the intelligence of the network. The introduction of the overlay meets the elasticity requirements and simplifies network management. The complexity of the network now moves to the software layer at the edge of the network, allowing the physical underlay to simply forward packets as fast as possible. Pushing the complexity to the edge of the network allows the network to be managed in a more efficient way. It eliminates the box by box mentality and utilizes a centralised view of the network. MATT CONRAN READ MORE