克隆一個ryu虛擬機器（1號） ，得到2號ryu虛擬機器

開啟1，2號ryu控制器：進入ryu/ryu/app目錄，然後啟動相應模組：sudo ryu-manager --verbose simple_switch_13.py ofctl_rest.py rest_topology.py

mininet虛擬機器中，在桌面上自定義一個topo檔案，如：sudo gedit 1.py

1.py的內容：

#!/usr/bin/python

from mininet.net import Mininet
from mininet.node import Controller, RemoteController
 
from mininet.cli import CLI
from mininet.log import setLogLevel, info

def myNet():


    #c0
    c0_IP='192.168.231.131'

    #c1
    c1_IP='192.168.231.133'

    net = Mininet( topo=None, build=False)

    # Create nodes
    h1 = net.addHost( 'h1', mac='01:00:00:00:01:00', ip='192.168.0.1/24' )
    h2 = net.addHost( '
 
h2', mac='01:00:00:00:02:00', ip='192.168.0.2/24' )

    # Create switches
    s1 = net.addSwitch( 's1', listenPort=6634, mac='00:00:00:00:00:01' )
    s2 = net.addSwitch( 's2', listenPort=6634, mac='00:00:00:00:00:02' )

    print "*** Creating links"
    net.addLink(h1, s1, )
    net.addLink(h2, s2, )
    net.addLink(s1, s2, )

    
 
# Add Controllers
    c0_ctrl = net.addController( 'c0', controller=RemoteController, ip=c0_IP, port=6653)

    c1_ctrl = net.addController( 'c1', controller=RemoteController, ip=c1_IP, port=6653)


    net.build()

    # Connect each switch to a different controller
    s1.start( [c0_ctrl] )
    s2.start( [c1_ctrl] )

    s1.cmdPrint('ovs-vsctl show')

    CLI( net )
    net.stop()

if __name__ == '__main__':
    setLogLevel( 'info' )
    myNet()

在終端執行該檔案：sudo python 1.py

可以發現：交換機s1的master控制器為1號ryu控制器，s2的master控制器為2號ryu控制器。

如果想進行控制器角色轉換，比如s1的master控制器設定為2號ryu控制器，使用命令：

sudo ovs-vsctl set-controller s1 tcp:192.168.231.133:6653

此時再次檢視sudo ovs-vsctl show，發現角色轉變成功。