实验2:Open vSwitch虚拟交换机实践
一、实验目的
- 能够对Open vSwitch进行基本操作;
- 能够通过命令行终端使用OVS命令操作Open vSwitch交换机,管理流表;
- 能够通过Mininet的Python代码运行OVS命令,控制网络拓扑中的Open vSwitch交换机
二、实验环境
Ubuntu 20.04 Desktop amd64
三、实验要求
(一)基本要求
-
ovs-vsctl基础操作实践:创建OVS交换机,以ovs-xxxxxxxxx命名,其中xxxxxxxxx为本人学号。在创建的交换机上增加端口p0和p1,设置p0的端口号为100,p1的端口号为101,类型均为internal;为了避免网络接口上的地址和本机已有网络地址冲突,需要创建虚拟网络空间(参考命令netns)ns0和ns1,分别将p0和p1移入,并分别配置p0和p1端口的ip地址为190.168.1.100、192.168.1.101,子网掩码为255.255.255.0;最后测试p0和p1的连通性。
-
使用Mininet搭建的SDN拓扑,如下图所示,要求支持OpenFlow 1.3协议,主机名、交换机名以及端口对应正确。
-
通过命令行终端输入“ovs-ofctl”命令,直接在s1和s2上添加流表,划分出所要求的VLAN。
VLAN_ID | Hosts |
---|---|
0 | h1 h3 |
1 | h2 h4 |
- 主机连通性要求:
- h1 – h3互通
- h2 – h4互通
- 其余主机不通
(二)进阶要求
阅读SDNLAB实验使用Mininet,编写Python代码,生成(一)中的SDN拓扑,并在代码中直接使用OVS命令,做到可以直接运行Python程序完成和(一)相同的VLAN划分。
(三)实验报告
-
请用Markdown排版;
-
基础要求提交
a) /home/用户名/学号/lab2/目录下执行ovs-vsctl show命令、以及p0和p1连通性测试的执行结果截图;
b) /home/用户名/学号/lab2/目录下开启Mininet CLI并执行pingall命令的截图、上述目录下查看OVS流表的命令结果截图,wireshark抓包截图,其余文字请勿赘述,否则扣分;
- 进阶要求为选做,有完成的同学请提交代码和执行结果截图,有完成比未完成的上机分数更高。
# submit_v1.py
'''
代码一次跑完,不能进入mininet界面继续操作;但所有的要求都可以在这里面直接实现
'''
from mininet.net import Mininet
from mininet.node import Node
# from mininet.link import TCLink
from mininet.link import Link
from mininet.log import setLogLevel, info
def myNet():
"Create network from scratch using Open vSwitch."
info( "*** Creating nodes\n" )
switch1 = Node( 's1', inNamespace=False )
switch2 = Node( 's2', inNamespace=False )
h1 = Node( 'h1' )
h2 = Node( 'h2' )
h3 = Node( 'h3' )
h4 = Node( 'h4' )
info( "*** Creating links\n" )
Link( h1, switch1 )
Link( h2, switch1 )
Link( h3, switch2 )
Link( h4, switch2 )
Link( switch1, switch2 )
info( "*** Configuring hosts\n" )
h1.setIP( '192.168.13.1/24' ) # h1 & h3
h2.setIP( '192.168.24.1/24' )
h3.setIP( '192.168.13.2/24' )
h4.setIP( '192.168.24.2/24' ) # h2 & h4
info( "*** Starting network using Open vSwitch\n" )
# print( r"switch1.cmd( 'ovs-vsctl show' )" )
# info ( switch1.cmd( 'ovs-vsctl show' ) )
switch1.cmd( 'ovs-vsctl del-br dp0' )
switch1.cmd( 'ovs-vsctl add-br dp0' )
# print( r"switch1.cmd( 'ovs-ofctl show dp0' )" )
# info( switch1.cmd( 'ovs-ofctl show dp0' ) )
switch2.cmd( 'ovs-vsctl del-br dp1' )
switch2.cmd( 'ovs-vsctl add-br dp1' )
# print( r"switch2.cmd( 'ovs-ofctl show dp1' )" )
# info( switch2.cmd( 'ovs-ofctl show dp1' ) )
for intf in switch1.intfs.values():
print( intf )
switch1.cmd( 'ovs-vsctl add-port dp0 %s' % intf )
for intf in switch2.intfs.values():
print( intf )
switch2.cmd( 'ovs-vsctl add-port dp1 %s' % intf )
switch1.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')
switch1.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')
switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=0,actions=pop_vlan,output:1')
switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=1,actions=pop_vlan,output:2')
switch2.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')
switch2.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')
switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=0,actions=pop_vlan,output:1')
switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=1,actions=pop_vlan,output:2')
info( "*** Running test\n" ) # every ping request try 3 times
h1.cmdPrint( 'ping -c 3 ' + h2.IP() ) # h1 ping h2 unreachable
h1.cmdPrint( 'ping -c 3 ' + h3.IP() ) # h1 ping h3 ok
h1.cmdPrint( 'ping -c 3 ' + h4.IP() ) # h1 ping h4 unreachable
h2.cmdPrint( 'ping -c 3 ' + h3.IP() ) # h2 ping h3 unreachable
h2.cmdPrint( 'ping -c 3 ' + h4.IP() ) # h2 ping h4 ok
h3.cmdPrint( 'ping -c 3 ' + h4.IP() ) # h3 ping h4 unreachable
info( "*** print the streamtable\n" )
info( switch1.cmd( 'ovs-ofctl dump-flows dp0 -O OpenFlow13' ))
info( switch2.cmd( 'ovs-ofctl dump-flows dp1 -O OpenFlow13' ))
info( "*** Stopping network\n" )
switch1.cmd( 'ovs-vsctl del-br dp0' )
switch1.deleteIntfs()
switch2.cmd( 'ovs-vsctl del-br dp1' )
switch2.deleteIntfs()
info( '\n' )
if __name__ == '__main__':
setLogLevel( 'info' )
info( '*** Scratch network demo (kernel datapath)\n' )
Mininet.init()
myNet()
# submit_v2.py
'''
可以进入mininet
'''
from mininet.net import Mininet
from mininet.node import Controller, RemoteController, OVSController
from mininet.node import CPULimitedHost, Host, Node
from mininet.node import OVSKernelSwitch, UserSwitch
from mininet.node import IVSSwitch
from mininet.cli import CLI
from mininet.log import setLogLevel, info
from mininet.link import TCLink, Intf
from subprocess import call
def myNetwork():
net = Mininet( topo=None,
build=False,
ipBase='10.0.0.0/8')
info( '*** Adding controller\n' )
c0=net.addController(name='c0',
controller=Controller,
protocol='tcp',
port=6633)
info( '*** Add switches\n')
s1 = net.addSwitch('s1', cls=OVSKernelSwitch)
s2 = net.addSwitch('s2', cls=OVSKernelSwitch)
info( '*** Add hosts\n')
h1 = net.addHost('h1', cls=Host, ip='10.0.0.1', defaultRoute=None)
h2 = net.addHost('h2', cls=Host, ip='10.0.0.2', defaultRoute=None)
h3 = net.addHost('h3', cls=Host, ip='10.0.0.3', defaultRoute=None)
h4 = net.addHost('h4', cls=Host, ip='10.0.0.4', defaultRoute=None)
info( '*** Add links\n')
net.addLink(h1, s1, 1, 1)
net.addLink(h2, s1, 1, 2)
net.addLink(s1, s2, 3, 3)
net.addLink(h4, s2, 1, 2)
net.addLink(h3, s2, 1, 1)
info( '*** Starting network\n')
net.build()
info( '*** Starting controllers\n')
for controller in net.controllers:
controller.start()
info( '*** Starting switches\n')
net.get('s1').start([c0])
net.get('s2').start([c0])
#添加流表,完成VLAN划分
info("*** Send the flow table down\n\n")
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,dl_vlan=0,actions=pop_vlan,output=1')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,dl_vlan=1,actions=pop_vlan,output=2')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,dl_vlan=0,actions=pop_vlan,output=1')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,dl_vlan=1,actions=pop_vlan,output=2')
info( '*** Post configure switches and hosts\n')
CLI(net)
net.stop()
if __name__ == '__main__':
setLogLevel( 'info' )
myNetwork()
- 个人总结,包括但不限于实验难度、实验过程遇到的困难及解决办法,个人感想,不少于200字。
两个子网的VLAN_ID
我一直没有在课堂上搞懂到底应该怎么区分,但是在实践中,我很容易就想清楚了具体的VLAN
一个是怎么样的情况,也了解了跨交换机的子网划分。
抓包工具wireshark
我还是第一次使用,一开始一直搞不清楚到底怎么打开它的界面,选取哪个端口;后来在同学的帮助下才了解具体的操作。另外,也知道了,在进行添加流表和查看流表的操作时,拓扑结构必须处于运行状态。
最后的进阶实验,是有一定的难度的;而且时间对我而言也比较紧张。在借鉴了同学的经验后,我发现有两个比较好的实现方法(参上),最后静下心来,也是一次性就好了。
标签:info,ovs,vlan,cmd,交换机,vSwitch,net,Open,ofctl From: https://www.cnblogs.com/lcy20220907/p/16717789.html