diff --git a/scripts/ctrl-add-ext.sh b/scripts/ctrl-add-ext.sh
new file mode 100755
index 0000000..88be2f3
--- /dev/null
+++ b/scripts/ctrl-add-ext.sh
@@ -0,0 +1,29 @@
+#! /usr/bin/env python
+import sys
+import time
+import os
+import re
+import json
+import socket
+
+CONFIG_FILE=os.getenv("HOME") + "/ONOS/web/config.json"
+
+def read_config():
+  global controllers
+  f = open(CONFIG_FILE)
+  conf = json.load(f)
+  controllers = conf['controllers']
+  f.close()
+
+if __name__ == "__main__":
+  read_config()
+  controllers.pop(0) 
+  url = ""
+  for c in controllers:
+    url += " " + "tcp:%s:6633" % socket.gethostbyname(c)
+
+  switches = os.popen("sudo ovs-vsctl list-br").read().split("\n");
+  switches.remove('')
+  for s in switches:
+    print "set switch %s controller %s" % (s, url)  
+    os.popen("sudo ovs-vsctl set-controller %s %s" % (s, url) )