+* ``--port-topology=mode``
+
+ Set port topology, where mode is ``paired`` (the default) or ``chained``.
+
+ In ``paired`` mode, the forwarding is between pairs of ports, for example: (0,1), (2,3), (4,5).
+
+ In ``chained`` mode, the forwarding is to the next available port in the port mask, for example: (0,1), (1,2), (2,0).