实验2:Open vSwitch虚拟交换机实践

一、实验目的

  1. 能够对Open vSwitch进行基本操作;
  2. 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;
  3. 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

1.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p0p1,设置p0的端口号为100p1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netnsns0ns1,分别将p0p1移入,并分别配置p0p1端口的ip地址为190.168.1.100192.168.1.101,子网掩码为255.255.255.0;最后测试p0p1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。

代码

#!/usr/bin/python
 2  
 3 from mininet.net import Mininet
 4 from mininet.node import Node
 5 from mininet.link import Link
 6 from mininet.log import  setLogLevel, info
 7  
 8 def myNet():
 9     "Create network from scratch using Open vSwitch."
10  
11     info( "*** Creating nodes\n" )
12     switch1 = Node( 's1', inNamespace=False )
13     switch2 = Node( 's2', inNamespace=False )
14  
15     h1 = Node('h1')
16     h2 = Node('h2')
17     h3 = Node('h3')
18     h4 = Node('h4')
19 
20  
21     info( "*** Creating links\n" )
22     Link(h1, switch1)
23     Link(h2, switch1)
24     Link(h3, switch2)
25     Link(h4, switch2)
26     Link(switch1, switch2)
27  
28     info( "*** Configuring hosts\n" )
29     h1.setIP( '192.168.123.1/24' )
30     h2.setIP( '192.168.124.1/24' )
31     h3.setIP( '192.168.123.2/24' )
32     h4.setIP( '192.168.124.2/24' )
33        
34     info( "*** Starting network using Open vSwitch\n" )
35     switch1.cmd( 'ovs-vsctl del-br dp0' )
36     switch1.cmd( 'ovs-vsctl add-br dp0' )
37     switch2.cmd( 'ovs-vsctl del-br dp1' )
38     switch2.cmd( 'ovs-vsctl add-br dp1' )
39 
40 
41     for intf in switch1.intfs.values():
42         print (intf)
43         print (switch1.cmd( 'ovs-vsctl add-port dp0 %s' % intf ))
44 
45 
46     for intf in switch2.intfs.values():
47         print (intf)
48         print (switch2.cmd( 'ovs-vsctl add-port dp1 %s' % intf ))
49   
50     print (switch1.cmd(r'ovs-vsctl show'))
51  
52     print (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'))
53     print (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'))
54     print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=0,actions=pop_vlan,output:1'))
55     print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=1,actions=pop_vlan,output:2'))
56 
57     print (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'))
58     print (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'))
59     print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=0,actions=pop_vlan,output:1'))
60     print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=1,actions=pop_vlan,output:2'))
61 
62 
63     info( "*** Running test\n" )
64     h1.cmdPrint( 'ping -c 3 ' + h3.IP() )
65     h2.cmdPrint( 'ping -c 3 ' + h4.IP() )
66     h1.cmdPrint( 'ping -c 3 ' + h4.IP() )
67     h2.cmdPrint( 'ping -c 3 ' + h3.IP() )
68 
69 
70  
71     info( "*** Stopping network\n" )
72     switch1.cmd( 'ovs-vsctl del-br dp0' )
73     switch1.deleteIntfs()
74     switch2.cmd( 'ovs-vsctl del-br dp1' )
75     switch2.deleteIntfs()
76     info( '\n' )
77  
78 if __name__ == '__main__':
79     setLogLevel( 'info' )
80     info( '*** Scratch network demo (kernel datapath)\n' )
81     Mininet.init()
82     myNet()
posted @ 2022-10-03 19:48  密码石蜡  阅读(2)  评论(0编辑  收藏  举报