实验7：基于REST API的SDN北向应用实践

实验报告

1-1：搭建如下拓扑，连接OpenDatlight

• 创建拓扑
  sudo mn --topo=single,3 --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow10
• 连接OpenDatlight
  ./distribution-karaf-0.6.4-Carbon/bin/karaf

1-2：编写Python程序，调用OpenDaylight的北向接口下发指令删除s1上的流表数据。

1-3：编写Python程序，调用OpenDaylight的北向接口下发硬超时流表，实现拓扑内主机h1和h3网络中断20s。

• 下发流表
  
• 流表
  
• 结果
  

1-4：编写Python程序，调用OpenDaylight的北向接口获取s1上活动的流表数。

• 结果
  

2-1：编写Python程序，调用Ryu的北向接口，实现上述OpenDaylight实验拓扑上相同的硬超时流表下发。

• 下发流表
  
• 流表
  
• 结果
  

2-2：利用Mininet平台搭建下图所示网络拓扑，要求支持OpenFlow 1.3协议，主机名、交换机名以及端口对应正确。拓扑生成后需连接Ryu，且Ryu应能够提供REST API服务。

• topo.py
  
• 连接ryu
  
• 构建拓扑
  

整理一个Shell脚本，参考Ryu REST API的文档，利用curl命令，实现和实验2相同的VLAN。

VLAN_ID	Hosts
0	h1 h3
1	h2 h4

• 先运行指令删除流表
  curl -X DELETE http://localhost:8080/stats/flowentry/clear/1
curl -X DELETE http://localhost:8080/stats/flowentry/clear/2
• 编写shell脚本

curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "in_port": 1
    },
    "actions":[
        {
            "type": "PUSH_VLAN",     
            "ethertype": 33024       
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",    
            "value": 4096            
        },
        {
            "type": "OUTPUT",
            "port": 3
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "in_port": 2
    },
    "actions":[
        {
            "type": "PUSH_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",     
            "value": 4097           
        },
        {
            "type": "OUTPUT",
            "port": 3
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "vlan_vid": 0
    },
    "actions":[
        {
            "type": "POP_VLAN",    
            "ethertype": 33024       
        },
        {
            "type": "OUTPUT",
            "port": 1
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 1,
    "priority": 1,
    "match":{
        "vlan_vid": 1
    },
    "actions":[
        {
            "type": "POP_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 2,
    "priority": 1,
    "match":{
        "in_port": 1
    },
    "actions":[
        {
            "type": "PUSH_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",    
            "value": 4096          
        },
        {
            "type": "OUTPUT",
            "port": 3
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 2,
    "priority": 1,
    "match":{
        "in_port": 2
    },
    "actions":[
        {
            "type": "PUSH_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "SET_FIELD",
            "field": "vlan_vid",   
            "value": 4097           
        },
        {
            "type": "OUTPUT",
            "port": 3
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 2,
    "priority": 1,
    "match":{
        "vlan_vid": 0
    },
    "actions":[
        {
            "type": "POP_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "OUTPUT",
            "port": 1
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

 curl -X POST -d '{
    "dpid": 2,
    "priority": 1,
    "match":{
        "vlan_vid": 1
    },
    "actions":[
        {
            "type": "POP_VLAN",    
            "ethertype": 33024      
        },
        {
            "type": "OUTPUT",
            "port": 2
        }
    ]
 }' http://localhost:8080/stats/flowentry/add

• 运行shell脚本
  
• pingall结果
  

实验总结

本次实验难度较大，需要编写大量代码来实现。由于没学过编写相关代码，做起来有点难度。在实验中遇到了挺多问题，在连接ryu的时候直接在ryu文件夹下调用连接指令,结果导致连接错误。在创建拓扑的时候，由于先连接ryu后创建拓扑，导致拓扑的pingall全不通。以及调用shell脚本时，没有用
curl -X DELETE http://localhost:8080/stats/flowentry/clear/1
curl -X DELETE http://localhost:8080/stats/flowentry/clear/2
来删除流表，导致出错。调用指令时显示curl未安装，调用
sudo apt-get install curl
安装解决问题
通过这次实验，学到了通过用编写程序用opendaylight或ryu对网络的北向接口进行控制，以及划分vlan网络