diff --git a/web/preset_flow.py b/web/preset_flow.py
new file mode 100755
index 0000000..626a2ba
--- /dev/null
+++ b/web/preset_flow.py
@@ -0,0 +1,25 @@
+#! /usr/bin/env python
+import itertools
+import sys
+
+src_port=1
+dst_port=1
+
+n=int(sys.argv[1])
+a=range(2,n+1)
+nflow=int(sys.argv[2])
+
+print "# For %d nodes cluster, %d flows per network pair, total %d flows" % (n, nflow, (n-1)*(n-2)/2 * nflow * 2)
+
+flow_id=1
+pair_id=1
+for i in itertools.combinations(a,2):
+  for f in range(2, nflow+2):
+    snet_id=int(i[0])
+    dnet_id=int(i[1])
+    term_id=f
+    print "%d ps_%d_1 00:00:00:00:00:00:%02x:%02x %d 00:00:00:00:00:00:%02x:%02x %d matchSrcMac 00:00:c0:a8:%02x:%02x matchDstMac 00:00:c0:a8:%02x:%02x" % (flow_id,pair_id,snet_id,term_id,src_port,dnet_id,term_id,dst_port,snet_id,term_id,dnet_id,term_id)
+    flow_id = flow_id + 1
+    print "%d ps_%d_2 00:00:00:00:00:00:%02x:%02x %d 00:00:00:00:00:00:%02x:%02x %d matchSrcMac 00:00:c0:a8:%02x:%02x matchDstMac 00:00:c0:a8:%02x:%02x" % (flow_id,pair_id,dnet_id,term_id,dst_port,snet_id,term_id,src_port,dnet_id,term_id,snet_id,term_id)
+    flow_id = flow_id + 1
+    pair_id = pair_id + 1