SDN第二次上机作业

from mininet.topo import Topo

class MyTopo(Topo):

    def __init__(self):

        # initilaize topology
        Topo.__init__(self)

        # add hosts and switches
        host1 = self.addHost(‘h1‘)
        host2 = self.addHost(‘h2‘)
        host3 = self.addHost(‘h3‘)
       
        switch1 = self.addSwitch(‘s1‘)
        switch2 = self.addSwitch(‘s2‘)
    switch3 = self.addSwitch(‘s3‘)
        switch4 = self.addSwitch(‘s4‘)

        # add links
        self.addLink(host1, switch2, 1, 1)
        self.addLink(switch2, switch1, 2, 1)
        self.addLink(host2, switch3, 1, 1)
        self.addLink(switch3, switch1, 2, 2)
    self.addLink(switch1, switch4, 3, 1)
    self.addLink(switch4, host3, 2, 1)
        
topos = {‘mytopo‘: (lambda: MyTopo())}