Bob Lantz
90 lines
2.8 KiB
Python
Executable File
90 lines
2.8 KiB
Python
Executable File
#!/usr/bin/python
|
|
|
|
"""
|
|
linuxrouter.py: Example network with Linux IP router
|
|
|
|
This example converts a Node into a router using IP forwarding
|
|
already built into Linux.
|
|
|
|
The example topology creates a router and three IP subnets:
|
|
|
|
- 192.168.1.0/24 (r0-eth1, IP: 192.168.1.1)
|
|
- 172.16.0.0/12 (r0-eth2, IP: 172.16.0.1)
|
|
- 10.0.0.0/8 (r0-eth3, IP: 10.0.0.1)
|
|
|
|
Each subnet consists of a single host connected to
|
|
a single switch:
|
|
|
|
r0-eth1 - s1-eth1 - h1-eth0 (IP: 192.168.1.100)
|
|
r0-eth2 - s2-eth1 - h2-eth0 (IP: 172.16.0.100)
|
|
r0-eth3 - s3-eth1 - h3-eth0 (IP: 10.0.0.100)
|
|
|
|
The example relies on default routing entries that are
|
|
automatically created for each router interface, as well
|
|
as 'defaultRoute' parameters for the host interfaces.
|
|
|
|
Additional routes may be added to the router or hosts by
|
|
executing 'ip route' or 'route' commands on the router or hosts.
|
|
"""
|
|
|
|
from mininet.topo import Topo
|
|
from mininet.net import Mininet
|
|
from mininet.node import Node
|
|
from mininet.log import setLogLevel, info
|
|
from mininet.cli import CLI
|
|
|
|
class LinuxRouter( Node ):
|
|
"A Node with IP forwarding enabled."
|
|
|
|
def config( self, **params ):
|
|
super( LinuxRouter, self).config( **params )
|
|
# Enable forwarding on the router
|
|
self.cmd( 'sysctl net.ipv4.ip_forward=1' )
|
|
|
|
def terminate( self ):
|
|
self.cmd( 'sysctl net.ipv4.ip_forward=0' )
|
|
super( LinuxRouter, self ).terminate()
|
|
|
|
|
|
class NetworkTopo( Topo ):
|
|
"A LinuxRouter connecting three IP subnets"
|
|
|
|
def build( self, **_opts ):
|
|
|
|
defaultIP = '192.168.1.1/24' # IP address for r0-eth1
|
|
router = self.addNode( 'r0', cls=LinuxRouter, ip=defaultIP )
|
|
|
|
s1, s2, s3 = [ self.addSwitch( s ) for s in 's1', 's2', 's3' ]
|
|
|
|
self.addLink( s1, router, intfName2='r0-eth1',
|
|
params2={ 'ip' : defaultIP } ) # for clarity
|
|
self.addLink( s2, router, intfName2='r0-eth2',
|
|
params2={ 'ip' : '172.16.0.1/12' } )
|
|
self.addLink( s3, router, intfName2='r0-eth3',
|
|
params2={ 'ip' : '10.0.0.1/8' } )
|
|
|
|
h1 = self.addHost( 'h1', ip='192.168.1.100/24',
|
|
defaultRoute='via 192.168.1.1' )
|
|
h2 = self.addHost( 'h2', ip='172.16.0.100/12',
|
|
defaultRoute='via 172.16.0.1' )
|
|
h3 = self.addHost( 'h3', ip='10.0.0.100/8',
|
|
defaultRoute='via 10.0.0.1' )
|
|
|
|
for h, s in [ (h1, s1), (h2, s2), (h3, s3) ]:
|
|
self.addLink( h, s )
|
|
|
|
|
|
def run():
|
|
"Test linux router"
|
|
topo = NetworkTopo()
|
|
net = Mininet( topo=topo ) # controller is used by s1-s3
|
|
net.start()
|
|
info( '*** Routing Table on Router:\n' )
|
|
print net[ 'r0' ].cmd( 'route' )
|
|
CLI( net )
|
|
net.stop()
|
|
|
|
if __name__ == '__main__':
|
|
setLogLevel( 'info' )
|
|
run()
|