How to use a pox controller with a default controller in Mininet

Question

I have a python script that aims to make a linear topology of length 2, with 2 controllers: a custom and standard pox. The ping between the hosts is not working and the only hint I have is: "You could rely on the L3_learning component documentation: ... "

from mininet.log import setLogLevel, info
from mininet.net import Mininet
from mininet.topolib import TreeTopo
from mininet.cli import CLI
from mininet.node import Controller, OVSSwitch
from os import environ

# DO NOT MODIFY THIS PART 

POXDIR = environ[ 'HOME' ] + '/pox'

class CustomPOX( Controller ):
    "Custom POX() subclass that connects defines the POX component to load"
    def __init__( self, name, cdir=POXDIR,
                  command='python pox.py',
                  cargs=( 'openflow.of_01 --port=%s '
                          'forwarding.l2_learning' ),
                  **kwargs ):
        Controller.__init__( self, name, cdir=cdir,
                             command=command,
                             cargs=cargs, **kwargs )

# controllers={ 'pox': POX }

class CustomSwitch( OVSSwitch ):
    "Custom Switch() subclass that connects to different controllers"
    def start( self, controllers ):
        return OVSSwitch.start( self, [ cmap[ self.name ] ] )


# THIS PART CAN BE CHANGED AND ADAPTED IF REQUIRED 

setLogLevel( 'info' )

def multiControllerNet():
   "Create a network from semi-scratch with multiple controllers."
c1 = CustomPOX ('pox', ip='127.0.0.1', port=6633)
c2 = Controller ('c2', port=6633)

cmap = {'s1': c1, 's2': c2}


net = Mininet( switch=CustomSwitch, build=False, waitConnected=True )

info( "*** Creating (reference) controllers\n" )
for c in [ c1, c2 ]:
    net.addController(c)

info( "*** Creating switches\n" )
s1 = net.addSwitch( 's1' )
s2 = net.addSwitch( 's2' )


info( "*** Creating hosts\n" )
h1 = net.addHost('host1', mac='00:00:00:00:10:01', ip='10.0.10.1/24')
h2 = net.addHost('host2', mac='00:00:00:00:20:01', ip='10.0.30.1/24')

info( "*** Creating links\n" )
net.addLink( s1, h1 )
net.addLink( s2, h2 )
net.addLink( s1, s2 )

info( "*** Starting network\n" )
net.build()
c1.start()
c2.start()
s1.start( [ c1 ] )
s2.start( [ c2 ] )

info( "*** Testing network\n" )
net.pingAll()

info( "*** Running CLI\n" )
CLI( net )

info( "*** Stopping network\n" )
net.stop()


if __name__ == '__main__':
    setLogLevel( 'info' )  # for CLI output
    multiControllerNet()

The annotations are not mine

First of all, I'm not sure why the hosts can't communicate. Because 2 switches under two different controllers are not linked by default?

I tried to swap l2 with l3 but it doesn't change anything, which is normal since reading the documentation, I don't see what the advantage would be in this situation. I tried to assign / change the ip addresses of the controllers but it had no effect.

Should I add a rule that the controllers must connect the switches? If so, is this topic (How to add flow rules in POX controller) the right solution? Because it doesn't seem to fit in the logic of my script.

Or is it more about changing / adding a parameter when I define my controllers?

Answer 1

Ok it's just change l2 with l3 and add ip route in CLI ( host1 ip route add 10.0.30.0/24 dev host1-eth0 / host2 ip route add 10.0.10.0/24 dev host2-eth0 ). L3 will broadcast if it don't know the host so -> connect with other switch. After that: start pox controller and ping works !