Change to tree topo for default reactive forwarding test
diff --git a/TestON/tests/ONOSNextTest/ONOSNextTest.topo b/TestON/tests/ONOSNextTest/ONOSNextTest.topo
index a10a91b..0f7388e 100755
--- a/TestON/tests/ONOSNextTest/ONOSNextTest.topo
+++ b/TestON/tests/ONOSNextTest/ONOSNextTest.topo
@@ -27,8 +27,9 @@
             <connect_order>3</connect_order>
             <COMPONENTS>
                 #Specify the Option for mininet
-                <arg1> </arg1>
+                <arg1> --topo tree,2,3</arg1>
                 <arg2> </arg2>
+                <arg3> </arg3>
                 <controller> remote </controller>
             </COMPONENTS>
         </Mininet1>