2019 SDN上机第6次作业

1. 实验拓扑

（1）创建test2.py文档

代码如下：

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

        # add switches and hosts  
        sw1 = self.addSwitch('s1')
        sw2 = self.addSwitch('s2')

        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,sw1,1,1)
        self.addLink(h2,sw1,1,2)
        self.addLink(h3,sw1,1,3)
        self.addLink(sw1,sw2,4,4)
        self.addLink(h4,sw2,1,1)
        self.addLink(h5,sw2,1,2)
        self.addLink(h6,sw2,1,3)

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

（2）输入具体命令如下，创建拓扑

sudo mn --custom ./test2.py --topo mytopo --controller=remote,ip=127.0.0.1,port=6653 --switch ovsk,protocols=OpenFlow13

（3）使用net命令查看拓扑并使用pingall命令测试所有节点连通性

2.使用Ryu的REST API下发流表实现和第2次实验同样的VLAN

（1）这里贴出s1和s2的脚本完整代码

#s1
#端口号1发来数据
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

#端口号2发来数据
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

#端口号3发来数据
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



#向端口1转发
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

#向端口2转发
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

#向端口3转发
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

#s2

#端口号1发来数据
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

#端口号2发来数据
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

#端口号3发来数据
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



#向端口1转发
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

#向端口2转发
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

#向端口3转发
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

实际上s2就是基于s1换个dpid就ok

（2）直接在命令行中执行

（3）查看下发流表结果

（4）查看s1和s2流表

sudo ovs-ofctl -O OpenFlow13 dump-flows s1
sudo ovs-ofctl -O OpenFlow13 dump-flows s2

（5）最后对比一下前后pingall的结果

3.对比两种方法，写出你的实验体会

  我们目前学习到的都是比较基础的基于实验去做一些操作，这两种方法都体现了流表的灵活性，这是SDN网络的优势之一。据我了解，利用这两种方法查看流表，验证网络功能，开发APP都具有非常重要的作用。
  对于上一次实验二使用的ovs方法，会比较简单，可以直接在 Open vSwitch 下发流表，但是在使用RYU的过程中，有时需要使用web拓扑，有时也需要通过API去下发流表等操作。这些操作在RYU中都会使用到RESTAPI。