pratica-1-III.py

#Exercise practice of the course Advanced Topics in Computer Networks at UFRPE/Brazil 
#Author: Kleber Leal and Glauco Goncalves, PhD

import atexit
from mininet.net import Mininet
from mininet.topo import Topo
from mininet.cli import CLI
from mininet.log import info,setLogLevel
from mininet.link import TCLink

net = None

def createTopo():
        topo=Topo()

        #Create Nodes
        topo.addHost("h1")
        topo.addHost("h2")
        topo.addHost("h3")
        topo.addHost("h4")
        topo.addSwitch('s1')
        topo.addSwitch('s2')
        topo.addSwitch('s3')

        #Create links
        topo.addLink('s1','s2',bw=100,delay='100ms',loss=10)
        topo.addLink('s1','s3')
        topo.addLink('h1','s2')
        topo.addLink('h2','s2')
        topo.addLink('h3','s3')
        topo.addLink('h4','s3')
        return topo

def startNetwork():
        topo = createTopo()
        global net
        net = Mininet(topo=topo, autoSetMacs=True, link=TCLink)
        net.start()
        CLI(net)

def stopNetwork():
        if net is not None:
                net.stop()

if __name__ == '__main__':
        atexit.register(stopNetwork)
        setLogLevel('info')
        startNetwork()