Dec 11, 2013
Overlay Networking: An Introduction
Software-defined networking is an umbrella term for a variety of emerging technologies that promise to bring more automation and scalability to enterprise networks, where manual configuration of switches and routers can’t keep pace with the near-instantaneous provisioning of virtual machines that require network access and policy controls.
One SDN option is a network overlay, in which tunnels are set up between virtual switches inside hypervisors. While the tunnels make use of the physical network to send packets, they don’t have to configure switches to get traffic to its destination. By contrast, other SDN approaches use methods such as OpenFlow to program switches.
This article looks at the technical underpinnings of network overlays, including tunnelling technology and protocols, and network agents. It also examines the integration of virtual and physical networks, including the use of VXLAN Termination End Points, or VTEPs. It also outlines the potential business value of overlays in the datacenter. (S7640113)