Delay/disruption tolerant networking (DTN) has recently been proposed as a very effective solution to cope with the problems posed by challenged networks (long delays, disruptions, absence of end-to-end connectivity, etc.). In order to assess DTN performance in such scenarios, it is essential to be able to rely on specific evaluation tools. In this paper we present DTNperf_2, which is a client-server evaluation tool designed to assess goodput and to provide logs in DTN bundle layer architectures. The aim is to facilitate the adoption of this tool by the DTN research community. DTNperf_2 features, design and usage are discussed in detail. Moreover, an example of use is given, to demonstrate its capabilities. DTNperf_2 is included in the official DTN suite available at DTNRG Web site.