2019 SDN上机第4次作业

1.用Python脚本搭建如下拓扑，连接OpenDayLight控制器

创建拓扑如下

from mininet.topo import Topo

class MyTopo(Topo):

    def __init__(self):

        # initilaize topology
        Topo.__init__(self)

        # add hosts and switches
        h1 = self.addHost('h1')
        h2 = self.addHost('h2')
        h3 = self.addHost('h3')

        s1 = self.addSwitch('s1')

        # add links
        self.addLink(h1, s1, 1, 1)
    self.addLink(h2, s1, 1, 2)
    self.addLink(h3, s1, 1, 3)
        
topos = {'mytopo': (lambda: MyTopo())}

通过命令执行文件

sudo mn --custom a.py --topo mytopo --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

使用pingall命令测试连通性

控制器端的拓扑图

2.在控制器提供的WEB UI中下发流表使h2 20s内ping不通h3，20s后恢复

依次打开：Yang UI>Opendaylight-inventory>config>nodes>table>flow

首先使用links查询链路连接情况

可以看出h2连接s1的port2， h3连接s1的port3

故可以让下发策略使port2进来的目的IP为h3的数据包都drop掉，这样就可以ping不通

按一下方法设置即可，注意get要改成put

验证h2 ping h3中断又恢复

3.借助Postman通过OpenDayLight的北向接口下发流表，再利用OpenDayLight北向接口查看已下发的流表

对Postman的安装，下完安装包后，使用命令如下，即可安装成功

sudo tar -xzf Postman-linux-x64-7.11.0.tar.gz
./Postman/Postman

Postman下发流表及查看流表

http://127.0.0.1:8181/restconf/config/opendaylight-inventory:nodes/node/openflow:1/flow-node-inventory:table/0/flow/1

{
    "flow": [
        {
            "id": "1",
            "match": {
                "in-port": "2",
                "ethernet-match": {
                    "ethernet-type": {
                        "type": "0x0800"
                    }
                },
                "ipv4-destination": "10.0.0.3/32"
            },
            "instructions": {
                "instruction": [
                    {
                        "order": "0",
                        "apply-actions": {
                            "action": [
                                {
                                    "order": "0",
                                    "drop-action": {}
                                }
                            ]
                        }
                    }
                ]
            },
            "priority": "65535",
            "hard-timeout": "20",
            "table_id": "0"
        }
    ]
}

可使用postman下发流表

下发效果

使用postman的get来调用接口查看流表