diff --git a/core/experiment.py b/core/experiment.py
index 0b9ce40..ac22634 100644
--- a/core/experiment.py
+++ b/core/experiment.py
@@ -362,11 +362,12 @@ class Experiment(object):
         self.topo.command_to(self.topo_config.client,
                         "rm {}".format(Experiment.PING_OUTPUT))
         count = self.experiment_parameter.get(ExperimentParameter.PING_COUNT)
-        for i in range(0, self.topo_config.client_interface_count()):
-            cmd = self.ping_command(self.topo_config.get_client_ip(i),
-                 self.topo_config.get_server_ip(interface_index=0), n=count)
-            logging.info(cmd)
-            self.topo.command_to(self.topo_config.client, cmd)
+        for j in range(0, self.topo_config.server_interface_count()):
+            for i in range(0, self.topo_config.client_interface_count()):
+                cmd = self.ping_command(self.topo_config.get_client_ip(i),
+                    self.topo_config.get_server_ip(interface_index=j), n=count)
+                logging.info(cmd)
+                self.topo.command_to(self.topo_config.client, cmd)
 
     def ping_command(self, from_ip, to_ip, n=5):
         return "ping -c {} -I {} {} >> {}".format(n, from_ip, to_ip, Experiment.PING_OUTPUT)