Rename controllers.py to controllers2.py since it's less convenient.

examples/controllers2.py

@@ -0,0 +1,58 @@
+#!/usr/bin/python
+
+"""
+This example creates a multi-controller network from semi-scratch by
+using the net.add*() API and manually starting the switches and controllers.
+
+Note that one could also create a custom switch class and pass it into
+the Mininet() constructor.
+"""
+
+from mininet.net import Mininet
+from mininet.node import Controller, OVSSwitch
+from mininet.cli import CLI
+from mininet.log import setLogLevel
+
+def multiControllerNet():
+    "Create a network from semi-scratch with multiple controllers."
+
+    net = Mininet( controller=Controller, switch=OVSSwitch, build=False )
+
+    print "*** Creating (reference) controllers"
+    c1 = net.addController( 'c1', port=6633 )
+    c2 = net.addController( 'c2', port=6634 )
+
+    print "*** Creating switches"
+    s1 = net.addSwitch( 's1' )
+    s2 = net.addSwitch( 's2' )
+
+    print "*** Creating hosts"
+    hosts1 = [ net.addHost( 'h%d' % n ) for n in 3, 4 ]
+    hosts2 = [ net.addHost( 'h%d' % n ) for n in 5, 6 ]
+
+    print "*** Creating links"
+    for h in hosts1:
+        s1.linkTo( h )
+    for h in hosts2:
+        s2.linkTo( h )
+    s1.linkTo( s2 )
+
+    print "*** Starting network"
+    net.build()
+    c1.start()
+    c2.start()
+    s1.start( [ c1 ] )
+    s2.start( [ c2 ] )
+
+    print "*** Testing network"
+    net.pingAll()
+
+    print "*** Running CLI"
+    CLI( net )
+
+    print "*** Stopping network"
+    net.stop()
+
+if __name__ == '__main__':
+    setLogLevel( 'info' )  # for CLI output
+    multiControllerNet()