SDN第一次上机作业

1.安装mininet

2.用字符命令生成拓扑
深度为2，扇出为3

测试连通性

3.用可视化生成拓扑

对应生成的命令行

测试连通性

4.用Python脚本生成一个Fat-tree型的拓扑
代码：

from mininet.topo import Topo
from mininet.net import Mininet
from mininet.node import RemoteController,CPULimitedHost
from mininet.link import TCLink
from mininet.util import dumpNodeConnections

class MyTopo( Topo ):
"Simple topology example."

def __init__( self ):
    "Create custom topo."

    # Initialize topology
    Topo.__init__( self )
    L1 = 2
    L2 = L1 * 2 
    L3 = L2
    c = []
    a = []
    e = []
      
    # add core ovs  
    for i in range( L1 ):
            sw = self.addSwitch( 'c{}'.format( i + 1 ) )
            c.append( sw )

    # add aggregation ovs
    for i in range( L2 ):
            sw = self.addSwitch( 'a{}'.format( i + 1 ) )
            a.append( sw )

    # add edge ovs
    for i in range( L3 ):
            sw = self.addSwitch( 'e{}'.format( i + 1 ) )
            e.append( sw )

    # add links between core and aggregation ovs
    for i in range( L1 ):
            sw1 = c[i]
            for j in range( L2 ):
            # self.addLink(sw2, sw1, bw=10, delay='5ms', loss=10, max_queue_size=1000, use_htb=True)  
                                sw2 = a[j]
		            self.addLink( sw2, sw1 )

    # add links between aggregation and edge ovs
    for i in range( 0, L2, 2 ):
            for sw1 in a[i:i+2]:
                for sw2 in e[i:i+2]:
		            self.addLink( sw2, sw1 )

    #add hosts and its links with edge ovs
    count = 1
    for sw1 in e:
            for i in range(2):
            	host = self.addHost( 'h{}'.format( count ) )
            	self.addLink( sw1, host )
            	count += 1

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

测试连通性