• Mininet 系列实验（七）

    • 实验内容

    本实验在基于 Mininet 脚本的不同拓扑环境下使用 OpenDaylight 控制交换机行为。任务一：一台交换机两台主机，从1端口进入的数据流转发到 2 端口，从 2 端口进入的数据流转发到1端口；任务二：两台交换机两台主机，主机 0 连接交换机 0，主机 1 连接交换机 1，交换机 0 连接交换机 1，数据转发端口同任务一；任务三：与任务二类似，但是在创建 link 的时候，设置带宽、延迟以及丢包率。

    • 参考

    Mininet脚本实现控制交换机行为

    • 实验环境

    虚拟机: Oracle VM VirtualBox Ubuntu16.04LTS

    • 实验步骤

    任务一：一台交换机两台主机，实现从 1 端口进入的数据流转发到 2 端口，从 2 端口进入的数据流转发到 1 端口。

    1.在~/mininet目录里新建文件 mymininet1.py

    # cd mininet
# touch mininet
# vim mymininet1.py

    脚本内容如下：

    #!/usr/bin/python 
from mininet.net import Mininet
from mininet.node import Node
from mininet.link import Link
from mininet.log import setLogLevel, info
from mininet.util import quietRun
 
from time import sleep
 
def scratchNet( cname='controller', cargs='-v ptcp:' ):
    "Create network from scratch using Open vSwitch."
 
    info( "*** Creating nodes
" )
    controller = Node( 'c0', inNamespace=False )
    switch0 = Node( 's0', inNamespace=False )
    h0 = Node( 'h0' )
    h1 = Node( 'h1' )
 
    info( "*** Creating links
" )
    Link( h0, switch0 )
    Link( h1, switch0 )
 
    info( "*** Configuring hosts
" )
    h0.setIP( '192.168.123.1/24' )
    h1.setIP( '192.168.123.2/24' )
    info( str( h0 ) + '
' )
    info( str( h1 ) + '
' )
 
    info( "*** Starting network using Open vSwitch
" )
    controller.cmd( cname + ' ' + cargs + '&' )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.cmd( 'ovs-vsctl add-br dp0' )
 
    for intf in switch0.intfs.values():
        print intf
        print switch0.cmd( 'ovs-vsctl add-port dp0 %s' % intf )
    switch0.cmd( 'ovs-vsctl set-controller dp0 tcp:10.0.2.15:6633' )
    # 这里的 IP 地址改为自己本机的，例如我的是10.0.2.15
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=1 actions=output:2"' )
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=2 actions=output:1"' )
 
    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 -c6 ' + h1.IP() )
    h1.cmdPrint( 'ping -c6 ' + h0.IP() )
 
    info( "*** Stopping network
" )
    controller.cmd( 'kill %' + cname )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.deleteIntfs()
    info( '
' )
 
if __name__ == '__main__':
    setLogLevel( 'info' )
    info( '*** Scratch network demo (kernel datapath)
' )
    Mininet.init()
    scratchNet()

    2.执行该脚本

    # python mymininet1.py

    任务1

    任务二：两台交换机两台主机，主机 0 连接交换机 0，主机 1 连接交换机 1，交换机 0 连接交换机 1，数据转发端口要求同任务一。

    1.在~/mininet目录里新建文件 mymininet2.py

    # cd mininet
# touch mininet
# vim mymininet2.py

    脚本内容如下：

    #!/usr/bin/python 
from mininet.net import Mininet
from mininet.node import Node
from mininet.link import Link
from mininet.log import setLogLevel, info
from mininet.util import quietRun
 
from time import sleep
 
def scratchNet( cname='controller', cargs='-v ptcp:' ):
    "Create network from scratch using Open vSwitch."
 
    info( "*** Creating nodes
" )
    controller = Node( 'c0', inNamespace=False )
    switch0 = Node( 's0', inNamespace=False )
    switch1 = Node( 's1', inNamespace=False )
    h0 = Node( 'h0' )
    h1 = Node( 'h1' )
 
    info( "*** Creating links
" )
    Link( h0, switch0 )
    Link( h1, switch1 )
    Link( switch0, switch1 )
 
    info( "*** Configuring hosts
" )
    h0.setIP( '192.168.123.1/24' )
    h1.setIP( '192.168.123.2/24' )
    info( str( h0 ) + '
' )
    info( str( h1 ) + '
' )
 
    info( "*** Starting network using Open vSwitch
" )
    controller.cmd( cname + ' ' + cargs + '&' )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.cmd( 'ovs-vsctl add-br dp0' )
    switch1.cmd( 'ovs-vsctl del-br dp1' )
    switch1.cmd( 'ovs-vsctl add-br dp1' )
 
 
    for intf in switch0.intfs.values():
        print intf
        print switch0.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 )
 
    switch0.cmd( 'ovs-vsctl set-controller dp0 tcp:10.0.0.8:6633' )
    # 这里的 IP 地址改为自己本机的，例如我的是10.0.2.15
    switch1.cmd( 'ovs-vsctl set-controller dp1 tcp: 10.0.0.8:6633' )
    # 这里的 IP 地址改为自己本机的，例如我的是10.0.2.15
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=1 actions=output:2"' )
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=2 actions=output:1"' )
    switch1.cmd( 'ovs-ofctl add-flow dp1 "in_port=1 actions=output:2"' )
    switch1.cmd( 'ovs-ofctl add-flow dp1 "in_port=2 actions=output:1"' )
 
 
    info( '*** Waiting for switch to connect to controller' )
    while 'is_connected' not in quietRun( 'ovs-vsctl show' ):
        sleep( 1 )
        info( '.' )
    info( '
' )
    print switch0.cmd( 'ovs-ofctl show dp0' )
    print switch1.cmd( 'ovs-ofctl show dp1' )
 
 
    info( "*** Running test
" )
    h0.cmdPrint( 'ping -c3 ' + h1.IP() )
    h1.cmdPrint( 'ping -c3 ' + h0.IP() )
 
    info( "*** Stopping network
" )
    controller.cmd( 'kill %' + cname )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.deleteIntfs()
    switch1.cmd( 'ovs-vsctl del-br dp1' )
    switch1.deleteIntfs()
    info( '
' )
 
if __name__ == '__main__':
    setLogLevel( 'info' )
    info( '*** Scratch network demo (kernel datapath)
' )
    Mininet.init()
    scratchNet()

    2.执行该脚本

    # python mymininet2.py

    任务2_1
    任务2_2

    任务三：与任务二类似，但是在创建link的时候，设置带宽、延迟以及丢包率。

    1.在~/mininet目录里新建文件 mymininet3.py

    # cd mininet
# touch mininet
# vim mymininet3.py

    脚本内容如下：

    #!/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 mininet.util import quietRun
 
from time import sleep
 
def scratchNet( cname='controller', cargs='-v ptcp:' ):
    "Create network from scratch using Open vSwitch."
 
    info( "*** Creating nodes
" )
    controller = Node( 'c0', inNamespace=False )
    switch0 = Node( 's0', inNamespace=False )
    switch1 = Node( 's1', inNamespace=False )
    h0 = Node( 'h0' )
    h1 = Node( 'h1' )
 
    info( "*** Creating links
" )
 
    linkopts0=dict(bw=10)
    linkopts1=dict(bw=10, delay='5ms', loss=10)
    TCLink( h0, switch0,**linkopts0)
    TCLink( h1, switch1,**linkopts0)
    TCLink( switch0, switch1,**linkopts1)
 
 
    info( "*** Configuring hosts
" )
    h0.setIP( '192.168.123.1/24' )
    h1.setIP( '192.168.123.2/24' )
    info( str( h0 ) + '
' )
    info( str( h1 ) + '
' )
 
    info( "*** Starting network using Open vSwitch
" )
    controller.cmd( cname + ' ' + cargs + '&' )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.cmd( 'ovs-vsctl add-br dp0' )
    switch1.cmd( 'ovs-vsctl del-br dp1' )
    switch1.cmd( 'ovs-vsctl add-br dp1' )
 
 
    for intf in switch0.intfs.values():
        print intf
        print switch0.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 )
 
    switch0.cmd( 'ovs-vsctl set-controller dp0 tcp:10.0.0.8:6633' )
    # 这里的 IP 地址改为自己本机的，例如我的是10.0.2.15
    switch1.cmd( 'ovs-vsctl set-controller dp1 tcp: 10.0.0.8:6633' )
    # 这里的 IP 地址改为自己本机的，例如我的是10.0.2.15
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=1 actions=output:2"' )
    switch0.cmd( 'ovs-ofctl add-flow dp0 "in_port=2 actions=output:1"' )
    switch1.cmd( 'ovs-ofctl add-flow dp1 "in_port=1 actions=output:2"' )
    switch1.cmd( 'ovs-ofctl add-flow dp1 "in_port=2 actions=output:1"' )
 
 
    info( '*** Waiting for switch to connect to controller' )
    while 'is_connected' not in quietRun( 'ovs-vsctl show' ):
        sleep( 1 )
        info( '.' )
    info( '
' )
    print switch0.cmd( 'ovs-ofctl show dp0' )
    print switch1.cmd( 'ovs-ofctl show dp1' )
 
 
    info( "*** Running test
" )
    h0.cmdPrint( 'ping -c3 ' + h1.IP() )
    h1.cmdPrint( 'ping -c3 ' + h0.IP() )
 
    info( "*** Stopping network
" )
    controller.cmd( 'kill %' + cname )
    switch0.cmd( 'ovs-vsctl del-br dp0' )
    switch0.deleteIntfs()
    switch1.cmd( 'ovs-vsctl del-br dp1' )
    switch1.deleteIntfs()
    info( '
' )
 
if __name__ == '__main__':
    setLogLevel( 'info' )
    info( '*** Scratch network demo (kernel datapath)
' )
    Mininet.init()
    scratchNet()

    2.执行该脚本

    # python mymininet3.py

    任务3_1
    任务3_2

    • 总结

    1. 实验过程中遇到的问题

    • 一开始忘记修改代码中控制器的 IP 地址导致连接不上

    2. 收获

    • 熟悉 Mininet 自定义拓扑脚本的编写；
    • 掌握使用「ovs-vsctl」命令直接控制 Open vSwitch。
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  • 原文地址：https://www.cnblogs.com/multhree/p/9396580.html
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