Testing applications is important, as shows the rise of continuous integrationand automated testing. In this talk, I will focus on one area of testing thatis difficult to automate: poor network connectivity. Developers usually workwithin reliable networking conditions so they might not notice issues thatarise in other networking conditions. I will explain how traffic control onLinux can help to simulate various network connectivity. I will run a demowith Weave Scope showing how an application running in Kubernetes behaves whenchanging network parameters.