• 实验 3: Mininet 实验——测量路径的损耗率


    一、实验目的

    在实验 2 的基础上进一步熟悉 Mininet 自定义拓扑脚本, 以及与损耗率相关的设
    定; 初步了解 Mininet 安装时自带的 POX 控制器脚本编写,测试路径损耗率。

    二、实验步骤

    (1) 新建并编辑 pox 脚本 flowstat.py:

    在 pox 安装目录下(Mininet 完整安装包含了 pox)执行以下命令运行 pox 脚本
    $ ./pox.py flowstat

    #!/usr/bin/python
    # Copyright 2012 William Yu
    # wyu@ateneo.edu
    #
    # This file is part of POX.
    #
    # POX is free software: you can redistribute it and/or modify
    # it under the terms of the GNU General Public License as published by
    # the Free Software Foundation, either version 3 of the License, or
    # (at your option) any later version.
    #
    # POX is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    # GNU General Public License for more details.
    #
    # You should have received a copy of the GNU General Public License
    # along with POX. If not, see <http://www.gnu.org/licenses/>.
    #
     
    """
    This is a demonstration file created to show how to obtain flow 
    and port statistics from OpenFlow 1.0-enabled switches. The flow
    statistics handler contains a summary of web-only traffic.
    """
     
    # standard includes
    from pox.core import core
    from pox.lib.util import dpidToStr
    import pox.openflow.libopenflow_01 as of
    from pox.lib.addresses import IPAddr, EthAddr
     
    # include as part of the betta branch
    from pox.openflow.of_json import *
    from pox.lib.recoco import Timer
    import time
     
    log = core.getLogger()
     
    src_dpid = 0
    dst_dpid = 0
    input_pkts = 0
    output_pkts = 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 = "0%s" % (str(flock.tm_min))
      else:
        mins = str(flock.tm_min)
      if int(flock.tm_sec)<10:
        secs = "0%s" % (str(flock.tm_sec))
      else:
        secs = str(flock.tm_sec)
      then +="]%s.%s.%s" % (hrs,mins,secs)
      return then
     
    # handler for timer function that sends the requests to all the
    # switches connected to the controller.
    def _timer_func ():
      for connection in core.openflow._connections.values():
        connection.send(of.ofp_stats_request(body=of.ofp_flow_stats_request()))
        connection.send(of.ofp_stats_request(body=of.ofp_port_stats_request()))
      log.debug("Sent %i flow/port stats request(s)", len(core.openflow._connections))
     
    # handler to display flow statistics received in JSON format
    # structure of event.stats is defined by ofp_flow_stats()
    def _handle_flowstats_received (event):
       #stats = flow_stats_to_list(event.stats)
       #log.debug("FlowStatsReceived from %s: %s", dpidToStr(event.connection.dpid), stats)
       global src_dpid, dst_dpid, input_pkts, output_pkts
       #print "src_dpid=", dpidToStr(src_dpid), "dst_dpid=", dpidToStr(dst_dpid)
       for f in event.stats:
         if f.match.dl_type==0x0800 and f.match.nw_dst==IPAddr("192.168.123.2") and f.match.nw_tos==0x64 and event.connection.dpid==src_dpid: 
           #print "input: ", f.byte_count, f.packet_count
           input_pkts = f.packet_count
         if f.match.dl_type==0x0800 and f.match.nw_dst==IPAddr("192.168.123.2") and f.match.nw_tos==0x64 and event.connection.dpid==dst_dpid:
           #print "output: ", f.byte_count, f.packet_count  
           output_pkts = f.packet_count
           if input_pkts !=0:
             print getTheTime(), "Path Loss Rate =", (input_pkts-output_pkts)*1.0/input_pkts*100, "%"
     
    # handler to display port statistics received in JSON format
    def _handle_portstats_received (event):
       #print "
    <<<STATS-REPLY: Return PORT stats for Switch", event.connection.dpid,"at ",getTheTime()
       #for f in event.stats:
          #if int(f.port_no)<65534:
            #print "   PortNo:", f.port_no, " Fwd's Pkts:", f.tx_packets, " Fwd's Bytes:", f.tx_bytes, " Rc'd Pkts:", f.rx_packets, " Rc's Bytes:", f.rx_bytes
            #print "   PortNo:", f.port_no,  " TxDrop:", f.tx_dropped, " RxDrop:", f.rx_dropped, " TxErr:", f.tx_errors, " RxErr:", f.rx_errors, " CRC:", f.rx_crc_err, " Coll:", f.collisions 
      stats = flow_stats_to_list(event.stats)
      log.debug("PortStatsReceived from %s: %s", dpidToStr(event.connection.dpid), stats)
     
    def _handle_ConnectionUp (event):
      global src_dpid, dst_dpid
      print "ConnectionUp: ", dpidToStr(event.connection.dpid)
      for m in event.connection.features.ports:
        if m.name == "s0-eth0":
          src_dpid = event.connection.dpid
        elif m.name == "s1-eth0":
          dst_dpid = event.connection.dpid
     
      msg = of.ofp_flow_mod()
      msg.priority =1
      msg.idle_timeout = 0
      msg.match.in_port =1
      msg.actions.append(of.ofp_action_output(port = of.OFPP_ALL))
      event.connection.send(msg)
     
      msg = of.ofp_flow_mod()
      msg.priority =1
      msg.idle_timeout = 0
      msg.match.in_port =2
      msg.actions.append(of.ofp_action_output(port = of.OFPP_ALL))
      event.connection.send(msg)
     
      msg = of.ofp_flow_mod()
      msg.priority =10
      msg.idle_timeout = 0
      msg.hard_timeout = 0
      msg.match.dl_type = 0x0800
      msg.match.nw_tos = 0x64
      msg.match.in_port=1
      msg.match.nw_dst = "192.168.123.2"
      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.dl_type = 0x0800
      msg.match.nw_tos = 0x64
      msg.match.nw_dst = "192.168.123.1"
      msg.actions.append(of.ofp_action_output(port = 1))
      event.connection.send(msg)
        
    # main functiont to launch the module
    def launch ():
      # attach handsers to listners
      core.openflow.addListenerByName("FlowStatsReceived", 
        _handle_flowstats_received) 
      core.openflow.addListenerByName("PortStatsReceived", 
        _handle_portstats_received) 
      core.openflow.addListenerByName("ConnectionUp", _handle_ConnectionUp)
     
      # timer set to execute every five seconds
      Timer(1, _timer_func, recurring=True)
    

    (2) 编辑 Mininet 脚本 mymininet3.py ,设置丢包loss=0

    #!/usr/bin/python
     
    from mininet.net import Mininet
    from mininet.node import Node
    from mininet.link import TCLink
    from mininet.log import  setLogLevel, info
    from threading import Timer
    from mininet.util import quietRun
    from time import sleep
     
    def myNet(cname='controller', cargs='-v ptcp:'):
        "Create network from scratch using Open vSwitch."
        info( "*** Creating nodes
    " )
        controller = Node( 'c0', inNamespace=False )
        switch = Node( 's0', inNamespace=False )
        switch1 = Node( 's1', inNamespace=False )
        h0 = Node( 'h0' )
        h1 = Node( 'h1' )
        
        info( "*** Creating links
    " )     
        linkopts0=dict(bw=100, delay='1ms', loss=0)
        linkopts1=dict(bw=100, delay='1ms', loss=0) 
        link0=TCLink( h0, switch, **linkopts0) 
        link1 = TCLink( switch, switch1, **linkopts1) 
        link2 = TCLink( h1, switch1, **linkopts0) 
        #print link0.intf1, link0.intf2
        link0.intf2.setMAC("0:0:0:0:0:1")
        link1.intf1.setMAC("0:0:0:0:0:2")
        link1.intf2.setMAC("0:1:0:0:0:1") 
        link2.intf2.setMAC("0:1:0:0:0:2")
     
        info( "*** Configuring hosts
    " )
        h0.setIP( '192.168.123.1/24' )
        h1.setIP( '192.168.123.2/24' )
           
        info( "*** Starting network using Open vSwitch
    " )
        switch.cmd( 'ovs-vsctl del-br dp0' )
        switch.cmd( 'ovs-vsctl add-br dp0' )
        switch1.cmd( 'ovs-vsctl del-br dp1' )
        switch1.cmd( 'ovs-vsctl add-br dp1' )
     
        controller.cmd( cname + ' ' + cargs + '&' )     
        for intf in switch.intfs.values():
            print intf
            print switch.cmd( 'ovs-vsctl add-port dp0 %s' % intf )
        for intf in switch1.intfs.values():
            print intf
            print switch1.cmd( 'ovs-vsctl add-port dp1 %s' % intf )
       
        # Note: controller and switch are in root namespace, and we
        # can connect via loopback interface
        switch.cmd( 'ovs-vsctl set-controller dp0 tcp:127.0.0.1:6633' )
        switch1.cmd( 'ovs-vsctl set-controller dp1 tcp:127.0.0.1:6633' )
      
    
        info( '*** Waiting for switch to connect to controller' )
        while 'is_connected' not in quietRun( 'ovs-vsctl show' ):
            sleep( 1 )
            info( '.' )
        info( '
    ' )
     
        #info( "*** Running test
    " )
        h0.cmdPrint( 'ping -Q 0x64 -c 20 ' + h1.IP() )
        
        sleep( 1 ) 
        info( "*** Stopping network
    " )
        controller.cmd( 'kill %' + cname )
        switch.cmd( 'ovs-vsctl del-br dp0' )
        switch.deleteIntfs()
        switch1.cmd( 'ovs-vsctl del-br dp1' )
        switch1.deleteIntfs()
        info( '
    ' )
     
    if __name__ == '__main__':
        setLogLevel( 'info' )
        info( '*** Scratch network demo (kernel datapath)
    ' )
        Mininet.init()
        myNet()
    

    (3)将loss改为10

  • 相关阅读:
    启动一个线程是用run()还是start()? .
    多线程有几种实现方法?同步有几种实现方法?
    同步和异步有何异同,在什么情况下分别使用他们?举例说明。
    abstract的method是否可同时是static,是否可同时是native,是否可同时是synchronized?
    写clone()方法时,通常都有一行代码,是什么?
    解释Spring支持的几种bean的作用域。
    Spring结构?
    说说hibernate的三种状态之间如何转换?
    测试用例设计的原则是什么?目前主要的测试用例设计方法有哪些?
    一套完整的测试应该由哪些阶段组成?
  • 原文地址:https://www.cnblogs.com/ThreeSmall/p/13680965.html
Copyright © 2020-2023  润新知