We have built a router testbed that is connected to the Deter/Emist experimental infrastructure. Our goal is to create a semi-realistic testbed to conduct BGP experiments, measure and visualize their impact on network performance and stability. Such testbed is also useful for evaluating different security countermeasures. Our testbed architecture includes four components: routing topology, background traffic, data analysis and visualization. This paper describes how we launch two specific BGP attacks, (a)Multiple Origin AS and (b)route flap damping attacks, and the lessons learned.