介绍

拓扑如下：

在该环境下，假设H1 ping H4，初始的路由规则是S1-S2-S5，一秒后，路由转发规则变为S1-S3-S5，再过一秒，规则变为S1-S4-S5，然后再回到最初的转发规则S1-S2-S5。通过这个循环调度的例子动态地改变交换机的转发规则。

pox脚本

pox脚本lab_controller.py

不得不说这脚本问题是真的多。

 from pox.core import core

 import pox.openflow.libopenflow_01 as of

 from pox.lib.util import dpidToStr

 from pox.lib.addresses import IPAddr, EthAddr

 from pox.lib.packet.arp import arp

 from pox.lib.packet.ethernet import ethernet, ETHER_BROADCAST

 from pox.lib.packet.packet_base import packet_base

 from pox.lib.packet.packet_utils import *

 import pox.lib.packet as pkt

 from pox.lib.recoco import Timer

 import time

 log = core.getLogger()

 s1_dpid = 0

 s2_dpid = 0

 s3_dpid = 0

 s4_dpid = 0

 s5_dpid = 0

 s1_p1 = 0

 s1_p4 = 0

 s1_p5 = 0

 s1_p6 = 0

 s2_p1 = 0

 s3_p1 = 0

 s4_p1 = 0

 pre_s1_p1 = 0

 pre_s1_p4 = 0

 pre_s1_p5 = 0

 pre_s1_p6 = 0

 pre_s2_p1 = 0

 pre_s3_p1 = 0

 pre_s4_p1 = 0

 turn = 0

 def getTheTime():  # fuction to create a timestamp

     flock = time.localtime()

     then = "[%s-%s-%s" % (str(flock.tm_year),

                           str(flock.tm_mon), str(flock.tm_mday))

     if int(flock.tm_hour) < 10:

         hrs = "0%s" % (str(flock.tm_hour))

     else:

         hrs = str(flock.tm_hour)

     if int(flock.tm_min) < 10:

         mins = str(flock.tm_min)

         secs = "0%s" % (str(flock.tm_sec))

     else:

         secs = str(flock.tm_sec)

     then += "]%s.%s.%s" % (hrs, mins, secs)

     return then

 def _timer_func():

     global s1_dpid, s2_dpid, s3_dpid, s4_dpid, s5_dpid, turn

     # print getTheTime(), "sent the port stats request to s1_dpid"

     if turn == 0:

         msg = of.ofp_flow_mod()

         msg.command = of.OFPFC_MODIFY_STRICT

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.4"

         msg.actions.append(of.ofp_action_output(port=5))

         core.openflow.getConnection(s1_dpid).send(msg)

         turn = 1

         return

     if turn == 1:

         msg = of.ofp_flow_mod()

         msg.command = of.OFPFC_MODIFY_STRICT

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.4"

         msg.actions.append(of.ofp_action_output(port=6))

         core.openflow.getConnection(s1_dpid).send(msg)

         turn = 2

         return

     if turn == 2:

         msg = of.ofp_flow_mod()

         msg.command = of.OFPFC_MODIFY_STRICT

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.4"

         msg.actions.append(of.ofp_action_output(port=4))

         turn = 0

         return

 def _handle_portstats_received(event):

     global s1_p1, s1_p4, s1_p5, s1_p6, s2_p1, s3_p1, s4_p1

     global pre_s1_p1, pre_s1_p4, pre_s1_p5, pre_s1_p6, pre_s2_p1, pre_s3_p1, pre_s4_p1

     if event.connection.dpid == s1_dpid:

         for f in event.stats:

             if int(f.port_no) < 65534:

                 if f.port_no == 1:

                     pre_s1_p1 = s1_p1

                     s1_p1 = f.rx_packets

                 if f.port_no == 4:

                     pre_s1_p4 = s1_p4

                     s1_p4 = f.tx_packets

                     # s1_p4=f.tx_bytes

                 if f.port_no == 5:

                     pre_s1_p5 = s1_p5

                     s1_p5 = f.tx_packets

                 if f.port_no == 6:

                     pre_s1_p6 = s1_p6

                     s1_p6 = f.tx_packets

         for f in event.stats:

             if int(f.port_no) < 65534:

                 if f.port_no == 1:

                     pre_s2_p1 = s2_p1

                     s2_p1 = f.rx_packets

                     # s2_p1=f.rx_bytes

     if event.connection.dpid == s3_dpid:

         for f in event.stats:

             if int(f.port_no) < 65534:

                 if f.port_no == 1:

                     pre_s3_p1 = s3_p1

                     s3_p1 = f.rx_packets

     if event.connection.dpid == s4_dpid:

         for f in event.stats:

             if int(f.port_no) < 65534:

                 if f.port_no == 1:

                     pre_s4_p1 = s4_p1

                     s4_p1 = f.rx_packets

 def _handle_ConnectionUp(event):

     global s1_dpid, s2_dpid, s3_dpid, s4_dpid, s5_dpid

     print "ConnectionUp: ", dpidToStr(event.connection.dpid)

     # remember the connection dpid for switch

     for m in event.connection.features.ports:

         if m.name == "s1-eth1":

             s1_dpid = event.connection.dpid

             print "s1_dpid=", s1_dpid

         elif m.name == "s2-eth1":

             s2_dpid = event.connection.dpid

             print "s2_dpid=", s2_dpid

         elif m.name == "s3-eth1":

             s3_dpid = event.connection.dpid

             print "s3_dpid=", s3_dpid

         elif m.name == "s4-eth1":

             s4_dpid = event.connection.dpid

             print "s4_dpid=", s4_dpid

         elif m.name == "s5-eth1":

             s5_dpid = event.connection.dpid

             print "s5_dpid=", s5_dpid

     if s1_dpid <> 0 and s2_dpid <> 0 and s3_dpid <> 0 and s4_dpid <> 0:

         Timer(1, _timer_func, recurring=True)

 def _handle_PacketIn(event):

     global s1_dpid, s2_dpid, s3_dpid, s4_dpid, s5_dpid

     packet = event.parsed

     if event.connection.dpid == s1_dpid:

         a = packet.find('arp')

         if a and a.protodst == "10.0.0.4":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=4))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.5":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=5))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.6":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=6))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.1":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=1))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.2":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=2))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.3":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=3))

             event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.1"

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.2"

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.3"

         msg.actions.append(of.ofp_action_output(port=3))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 1

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.4"

         msg.actions.append(of.ofp_action_output(port=4))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.5"

         msg.actions.append(of.ofp_action_output(port=5))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.6"

         msg.actions.append(of.ofp_action_output(port=6))

         event.connection.send(msg)

     elif event.connection.dpid == s2_dpid:

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

     elif event.connection.dpid == s3_dpid:

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

     elif event.connection.dpid == s4_dpid:

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 1

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0806

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 10

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.in_port = 2

         msg.match.dl_type = 0x0800

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

     elif event.connection.dpid == s5_dpid:

         a = packet.find('arp')

         if a and a.protodst == "10.0.0.4":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=4))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.5":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=5))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.6":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=6))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.1":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=1))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.2":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=2))

             event.connection.send(msg)

         if a and a.protodst == "10.0.0.3":

             msg = of.ofp_packet_out(data=event.ofp)

             msg.actions.append(of.ofp_action_output(port=3))

             event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.1"

         msg.actions.append(of.ofp_action_output(port=1))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.2"

         msg.actions.append(of.ofp_action_output(port=2))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.3"

         msg.actions.append(of.ofp_action_output(port=3))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.4"

         msg.actions.append(of.ofp_action_output(port=4))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.5"

         msg.actions.append(of.ofp_action_output(port=5))

         event.connection.send(msg)

         msg = of.ofp_flow_mod()

         msg.priority = 100

         msg.idle_timeout = 0

         msg.hard_timeout = 0

         msg.match.dl_type = 0x0800

         msg.match.nw_dst = "10.0.0.6"

         msg.actions.append(of.ofp_action_output(port=6))

         event.connection.send(msg)

 def launch():

     global start_time

     core.openflow.addListenerByName("PortStatsReceived", _handle_portstats_received)

     core.openflow.addListenerByName("ConnectionUp", _handle_ConnectionUp)

     core.openflow.addListenerByName("PacketIn", _handle_PacketIn)

mininet脚本

 #!/usr/bin/python

 from mininet.topo import Topo

 from mininet.net import Mininet

 from mininet.node import CPULimitedHost

 from mininet.link import TCLink

 from mininet.util import dumpNodeConnections

 from mininet.log import setLogLevel

 from mininet.node import Controller 

 from mininet.cli import CLI

 from functools import partial

 from mininet.node import RemoteController

 import os

 class MyTopo(Topo):

     "Single switch connected to n hosts."

     def __init__(self):

         Topo.__init__(self)

         s1=self.addSwitch('s1')

         s2=self.addSwitch('s2')

         s3=self.addSwitch('s3')

         s4=self.addSwitch('s4')

         s5=self.addSwitch('s5') 

         h1=self.addHost('h1')

         h2=self.addHost('h2')

         h3=self.addHost('h3')

         h4=self.addHost('h4')

         h5=self.addHost('h5')

         h6=self.addHost('h6')

         self.addLink(h1, s1, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True)

         self.addLink(h2, s1, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(h3, s1, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True)

         self.addLink(s1, s2, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s1, s3, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s1, s4, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s2, s5, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s3, s5, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True)  

         self.addLink(s4, s5, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s5, h4, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s5, h5, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

         self.addLink(s5, h6, bw=1, delay='10ms', loss=0, max_queue_size=1000, use_htb=True) 

 def perfTest():

     "Create network and run simple performance test"

     topo = MyTopo()

     net = Mininet(topo=topo, host=CPULimitedHost, link=TCLink, controller=partial(RemoteController, ip='127.0.0.1', port=6633))

     net.start()

     print "Dumping host connections"

     dumpNodeConnections(net.hosts)

     h1,h2,h3=net.get('h1','h2','h3')

     h4,h5,h6=net.get('h4','h5','h6')

     h1.setMAC("0:0:0:0:0:1")

     h2.setMAC("0:0:0:0:0:2")

     h3.setMAC("0:0:0:0:0:3")

     h4.setMAC("0:0:0:0:0:4")

     h5.setMAC("0:0:0:0:0:5")

     h6.setMAC("0:0:0:0:0:6")

     CLI(net)

     net.stop()

 if __name__ == '__main__':

     setLogLevel('info')

     perfTest()

如果是在不同的机器使用的pox将控制器ip修改到对应pox所在的ip，我使用的是同一台计算机上的就直接修改成了127.0.0.1。

然后运行pox脚本再运行mininet脚本，得到下图：

mininet运行没啥问题，不过提示0丢包率是非法的emmmmm。 然后pox的内容有些奇怪，咋感觉少了一句的感觉。强迫症，到脚本里填上。在第260行填上一行输出。得到下图：

鉴于有人说，h1 ping不到 h4，就先pingall一下，得到下图：

一切正常。 然后继续实验，在mininet输入h1 ping -i 0.1 h4 每秒从h1传送10个包到h4。

mininet界面到时挺正常的，但是pox界面emmm一片死寂，所以我反复了几次，结果没有变化。估计不是pox出问题了，就是pox脚本写的有问题吧，难不成是我实验环境有问题？

由于对脚本内容了解的不够，所以我先尝试了一下使用poxdesk图形界面来显示结果。先安装一下。

 cd ./pox/ext

 git clone https://github.com/MurphyMc/poxdesk

 cd poxdesk

 wget http://downloads.sourceforge.net/qooxdoo/qooxdoo-2.0.2-sdk.zip

 unzip qooxdoo-2.0.2-sdk.zip

 mv qooxdoo-2.0.2-sdk qx

 cd poxdesk

 ./generate.py

我的小水管算是把我卡死了

然后通过命令运行：

 ./pox.py 脚本名 web messenger messenger.log_service messenger.ajax_transport openflow.of_service poxdesk

然后进入浏览器查看：http://pox-ip:8000/poxdesk。这里pox-ip是pox所在的ip，如果本地就直接使用127.0.0.1就行。

观察s1目标为h4的，发现output一直在5和6之间变化，但是理论来说应该有三种不同的路由规则。结果很尴尬。。。

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