Virtual switches, like Open vSwitch, have emerged as an important part of cloud networking architectures. They connect interfaces of virtual machines and establish the connection to the outer network via physical network interface cards. Today, all important cloud frameworks support Open vSwitch as the default virtual switch. However, general understanding about the performance implications of Open vSwitch in different usage scenarios is missing. In this work we provide insights into the performance properties by systematically conducting measurements in virtual switching setups. We present quantitative and qualitative performance results of Open vSwitch in scenarios involving physical and virtual network interfaces.