#!/usr/bin/python

"""

This example shows how to add an interface (for example a real

hardware interface) to a network after the network is created.

"""

import re

from mininet.cli import CLI

from mininet.log import setLogLevel, info, error

from mininet.net import Mininet

from mininet.topolib import TreeTopo

from mininet.util import quietRun

def checkIntf( intf ):

"Make sure intf exists and is not configured."

if ( ' %s:' % intf ) not in quietRun( 'ip link show' ):

error( 'Error:', intf, 'does not exist!\n' )

exit( 1 )

ips = re.findall( r'\d+\.\d+\.\d+\.\d+', quietRun( 'ifconfig ' + intf ) )

if ips:

error( 'Error:', intf, 'has an IP address,'

'and is probably in use!\n' )

exit( 1 )

if __name__ == '__main__':

setLogLevel( 'info' )

newIntf = 'eth1'

info( '*** Checking', newIntf, '\n' )

checkIntf( newIntf )

info( '*** Creating network\n' )

net = Mininet( topo=TreeTopo( depth=1, fanout=2 ) )

switch = net.switches[ 0 ]

info( '*** Adding', newIntf, 'to switch', switch.name, '\n' )

switch.addIntf( newIntf )

net.start()

CLI( net )

net.stop()