Modbus 通訊協議詳解
阿新 • • 發佈:2020-09-22
一、實驗環境
- Oracle VM VirtualBox 虛擬機器環境
- ubuntu-16.04.7-desktop-amd64
二、實驗目的
- Mininet 安裝之後,會連帶安裝 Open vSwitch,可以直接通過 Python 指令碼呼叫
- Open vSwitch 命令,從而直接控制 Open vSwitch,通過實驗瞭解呼叫控制的方法。
三、實驗過程
學習SDNLAB中的ovsSingleBr.py 和 ovsMultiBr.py,按照下圖拓撲實現一個VLAN。
程式碼如下:
from mininet.net import Mininet from mininet.node import Node from mininet.link import TCLink from mininet.log import setLogLevel, info def myNet(): "Create network from scratch using Open vSwitch." info( "*** Creating nodes\n" ) switch0 = Node( 's0', inNamespace=False ) switch1 = Node( 's1', inNamespace=False ) h0 = Node( 'h0' ) h1 = Node( 'h1' ) h2 = Node( 'h2' ) h3 = Node( 'h3' ) info( "*** Creating links\n" ) linkopts0=dict(bw=100, delay='1ms', loss=0) linkopts1=dict(bw=1, delay='100ms', loss=0) TCLink( h0, switch0, **linkopts0) TCLink( h1, switch0, **linkopts0) TCLink( h2, switch1, **linkopts0) TCLink( h3, switch1, **linkopts0) TCLink( switch0, switch1, **linkopts1) info( "*** Configuring hosts\n" ) h0.setIP( '192.168.123.1/24' ) h1.setIP( '192.168.123.2/24' ) h2.setIP( '192.168.123.3/24' ) h3.setIP( '192.168.123.4/24' ) info( "*** Starting network using Open vSwitch\n" ) 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 ) print switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3') print switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3') print switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=0,actions=pop_vlan,output:1') print switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=1,actions=pop_vlan,output:2') print switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3') print switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3') print switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=0,actions=pop_vlan,output:1') print switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=1,actions=pop_vlan,output:2') #switch0.cmd('tcpdump -i s0-eth0 -U -w aaa &') #h0.cmd('tcpdump -i h0-eth0 -U -w aaa &') info( "*** Running test\n" ) h0.cmdPrint( 'ping -Q 0x90 -c 3 ' + h1.IP() ) h0.cmdPrint( 'ping -Q 0x90 -c 3 ' + h2.IP() ) h0.cmdPrint( 'ping -Q 0x90 -c 3 ' + h3.IP() ) h1.cmdPrint( 'ping -Q 0x90 -c 3 ' + h2.IP() ) h1.cmdPrint( 'ping -Q 0x90 -c 3 ' + h3.IP() ) h2.cmdPrint( 'ping -Q 0x90 -c 3 ' + h3.IP() ) #h1.cmdPrint('iperf -s -p 12345 -u &') #h0.cmdPrint('iperf -c ' + h1.IP() +' -u -b 10m -p 12345 -t 10 -i 1') #print switch0.cmd( 'ovs-ofctl show dp0' ) #print switch1.cmd( 'ovs-ofctl show dp1' ) #print switch2.cmd( 'ovs-ofctl show dp2' ) #print switch3.cmd( 'ovs-ofctl show dp3' ) #print switch4.cmd( 'ovs-ofctl show dp4' ) #print switch0.cmd( 'ovs-ofctl dump-tables dp0' ) #print switch0.cmd( 'ovs-ofctl dump-ports dp0' ) #print switch0.cmd( 'ovs-ofctl dump-flows dp0' ) #print switch0.cmd( 'ovs-ofctl dump-aggregate dp0' ) #print switch0.cmd( 'ovs-ofctl queue-stats dp0' ) #print "Testing video transmission between h1 and h2" #h1.cmd('./myrtg_svc -u > myrd &') #h0.cmd('./mystg_svc -trace st 192.168.123.2') info( "*** Stopping network\n" ) switch0.cmd( 'ovs-vsctl del-br dp0' ) switch0.deleteIntfs() switch1.cmd( 'ovs-vsctl del-br dp1' ) switch1.deleteIntfs() info( '\n' ) if __name__ == '__main__': setLogLevel( 'info' ) info( '*** Scratch network demo (kernel datapath)\n' ) Mininet.init() myNet()
執行結果如下: