"Library of potentially useful topologies for Mininet"

from mininet.topo import Topo, Node

from mininet.net import Mininet

class TreeTopo( Topo ):

"Topology for a tree network with a given depth and fanout."

def __init__( self, depth=1, fanout=2 ):

super( TreeTopo, self ).__init__()

# Numbering: h1..N, sN+1..M

hostCount = fanout ** depth

self.hostNum = 1

self.switchNum = hostCount + 1

# Build topology

self.addTree( depth, fanout )

# Consider all switches and hosts 'on'

self.enable_all()

# It is OK that i is "unused" in the for loop.

# pylint: disable-msg=W0612

def addTree( self, depth, fanout ):

"""Add a subtree starting with node n.

returns: last node added"""

isSwitch = depth > 0

if isSwitch:

num = self.switchNum

self.switchNum += 1

else:

num = self.hostNum

self.hostNum += 1

self.add_node( num, Node( is_switch=isSwitch ) )

if isSwitch:

for i in range( 0, fanout ):

child = self.addTree( depth - 1, fanout )

self.add_edge( num, child )

return num

# pylint: enable-msg=W0612

def TreeNet( depth=1, fanout=2, **kwargs ):

"Convenience function for creating tree networks."

topo = TreeTopo( depth, fanout )

return Mininet( topo, **kwargs )