Dear Maintainer, * What led up to the situation? iperf -c x.x.x.x -d does not work * What exactly did you do (or not do) that was effective (orineffective)? as the client (-c), bidirectional testing does not work. as the server (-s) and using 2.1.x as client, bidirectional testing works as expected. * What was the outcome of this action? only a single unidirectional test is run * What outcome did you expect instead? -d should run two unidirectional test