Support for
tunneling protocols (NVGRE, VxLAN etc.) and OpenFlow in top of rack switches allows physical hosts to participate in the virtualized network that connects virtual machines, see
Network Virtualization: a next generation modular platform for the data center virtual network. In this architecture, the top of rack switch replicates the functionality of the Open vSwitch (OVS) instances running on the hypervisors, allowing the controllers to flexibly integrate physical and virtual servers within the virtualized network.
Support for
sFlow and OpenFlow in the top of rack, virtual switches, and within the network fabric, provides the unified, data center wide, visibility and control needed to
optimize virtual machine placement,
improve network performance,
isolate performance between tenants and defend against
DDoS attacks.
