2019 SDN上机第6次作业

一、实验拓扑

1、实验拓扑

拓扑代码：

from mininet.topo import Topo
 
class MyTopo( Topo ):
    "Simple topology example."
 
    def __init__( self ):
        "Create custom topo."
 
        # Initialize topology
        Topo.__init__( self )
        L1 = 2
        L2 = L1 * 3
        s = []
        h = []
          
        for i in range( L1 ):
                sw = self.addSwitch( 's{}'.format( i + 1 ) )
                s.append( sw )
    
        self.addLink(s[0],s[1],4,4)
    
        count = 1
        for sw1 in s:
                for i in range(3):
                    host = self.addHost( 'h{}'.format( count ) )
                    self.addLink( sw1, host,i+1,1 )
                    count += 1
topos = { 'mytopo': ( lambda: MyTopo() ) }

拓扑图如下：

2、使用Python脚本完成拓扑搭建，并连接ryu控制器。实验代码如下：

from mininet.topo import Topo
class Topo2( Topo ):
    def __init__( self ):
        # Initialize topology
        Topo.__init__( self )

        # add switches  
        s1 = self.addSwitch('s1')
        s2 = self.addSwitch('s2')

    # add hosts  
        h1 = self.addHost('h1')
        h2 = self.addHost('h2')
        h3 = self.addHost('h3')
        h4 = self.addHost('h4')
        h5 = self.addHost('h5')
        h6 = self.addHost('h6')

        # add links
        self.addLink(h1,s1,1,1)
        self.addLink(h2,s1,1,2)
        self.addLink(h3,s1,1,3)
        self.addLink(s1,s2,4,4)
        self.addLink(h4,s2,1,1)
        self.addLink(h5,s2,1,2)
        self.addLink(h6,s2,1,3)

topos = { 'mytopo': ( lambda: Topo2() ) }

输入如下命令运行Python脚本x.py
sudo mn --custom ./sdn6.py --topo mytopo --controller=remote,ip=127.0.0.1,port=6653 --switch ovsk,protocols=OpenFlow13

终端输入pingall和net查看连接情况

pingall图

net图

进入文件夹的ryu文件夹下的app,连接ryu控制器

运行的代码如下：

ryu-manager ofctl_rest.py

二、使用Ryu的REST API下发流表实现和第2次实验同样的VLAN

编写脚本，脚本为sdn6.sh，内容如下：

curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "in_port":1
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4096            # 设置vlan_id的值
        },
        {
            "type": "OUTPUT",
            "port": 4
        }
    ]

}' http://127.0.0.1:8080/stats/flowentry/add





curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "in_port":2
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },

        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4097            # 设置vlan_id的值
        },
        {
            "type": "OUTPUT",
            "port": 4
        }
    ]
}' http://127.0.0.1:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "in_port":3
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4098            # 设置vlan_id的值
        },
        {
            "type": "OUTPUT",
            "port": 4
        }
    ]
}' http://127.0.0.1:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "dl_vlan": "0"
    },
    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 1
        }
    ]
}' http://localhost:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "dl_vlan": "1"
    },

    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '{
    "dpid": 1,
    "priority":1,
    "match":{
        "dl_vlan": "2"
    },
    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 3
        }
    ]
}' http://localhost:8080/stats/flowentry/add



curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "in_port":1
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4096            # 设置vlan_id的值
        },
        {
            "type": "OUTPUT",
            "port": 4
        }
    ]

}' http://127.0.0.1:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "in_port":2
    },

    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4097            # 设置vlan_id的值
        },
        {
            "type": "OUTPUT",
            "port": 4
        }
    ]
}' http://127.0.0.1:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "in_port":3
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     # s1将从主机发来的数据包打上vlan_tag
            "ethertype": 33024       # 帧类型0x8100(=33024): 表示IEEE 802.1Q的VLAN数据帧
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     # 设置VLAN ID
            "value": 4098            # 设置vlan_id的值
        },

        {
            "type": "OUTPUT",
            "port": 4
        }
    ]

}' http://127.0.0.1:8080/stats/flowentry/add



curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "dl_vlan": "0"
    },
    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 1
        }
    ]
}' http://localhost:8080/stats/flowentry/add


curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "dl_vlan": "1"
    },
    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]

}' http://localhost:8080/stats/flowentry/add

curl -X POST -d '{
    "dpid": 2,
    "priority":1,
    "match":{
        "dl_vlan": "2"
    },
    "actions":[
        {
            "type": "POP_VLAN",     # 给进入交换机的包去除 vlan_tag
        },
        {
            "type": "OUTPUT",
            "port": 3
        }

    ]

}' http://localhost:8080/stats/flowentry/add

现在可以打开终端运行sudo bash sdn6.sh
可以看到RYU控制器已接收流表项

查看s1和s2的流表
代码如下

sudo ovs-ofctl -O OpenFlow13 dump-flows s1

sudo ovs-ofctl -O OpenFlow13 dump-flows s2

再次查看连通性，发现已经连通

三、对比两种方法，写出你的实验体会

这次的实验和第二次的实验没有特别多的差别，原理都是一样的。
在上次实验二使用ovs了命令直接在交换机上下发流表实现VLAN，实验三这次实验是借助了RYU控制器，相比Open vSwitch在命令行下发流表，要方便许多。
在做实验的时候中间出了个差错，实验给停滞了，卡在了发送流表的地方，后面就给忘记了，这次被提醒才记起来，重启重做了一遍。