Complex distributed applications are highly depended on the quality of service of the underlying networks connecting their components. Common approaches for testing these applications may not be sufficient to ensure stability of a distributed system during networking issues. In this paper we try to explore the possibility of using lightweight virtualization for distributed application testing. Our approach is to use a set of tools provided by the Docker containerization platform to build a virtual network model of arbitrary topology with the tested application running inside. We explore scalability of this approach both when using one or more computers for modelling and try to show how the use of the developed simulation system named L3NS can allow developers to test and benchmark large-scale distributed systems e.g. blockchain networks.