from mininet.topo import Topo class MyTopo(Topo): def __init__(self): # initilaize topology Topo.__init__(self) # add hosts and switches h1 = self.addHost('h1') h2 = self.addHost('h2') h3 = self.addHost('h3') h4 = self.addHost('h4') sw1 = self.addSwitch('s1') sw2 = self.addSwitch('s2') sw3 = self.addSwitch('s3') sw4 = self.addSwitch('s4') # add links self.addLink(sw1,h1, 1, 1) self.addLink(sw1,sw2, 2, 1) self.addLink(sw1,sw3, 3, 1) self.addLink(sw1,sw4, 4, 1) self.addLink(sw2,sw4, 2, 2) self.addLink(sw3,sw4, 2, 3) self.addLink(sw4,h2, 4 ,1) self.addLink(sw4,h3, 5, 1) self.addLink(sw4,h4, 6, 1) topos = {'mytopo': (lambda: MyTopo())}