"Library of potentially useful topologies for Mininet"

from mininet.topo import Topo

from mininet.net import Mininet

# The build() method is expected to do this:

# pylint: disable=arguments-differ

class TreeTopo( Topo ):

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

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

# Numbering: h1..N, s1..M

self.hostNum = 1

self.switchNum = 1

# Build topology

self.addTree( depth, fanout )

def addTree( self, depth, fanout ):

"""Add a subtree starting with node n.

returns: last node added"""

isSwitch = depth > 0

if isSwitch:

node = self.addSwitch( 's%s' % self.switchNum )

self.switchNum += 1

for _ in range( fanout ):

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

self.addLink( node, child )

else:

node = self.addHost( 'h%s' % self.hostNum )

self.hostNum += 1

return node

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

"Convenience function for creating tree networks."

topo = TreeTopo( depth, fanout )

return Mininet( topo, **kwargs )

class TorusTopo( Topo ):

"""2-D Torus topology

WARNING: this topology has LOOPS and WILL NOT WORK

with the default controller or any Ethernet bridge

without STP turned on! It can be used with STP, e.g.:

# mn --topo torus,3,3 --switch lxbr,stp=1 --test pingall"""

def build( self, x, y ):

if x < 3 or y < 3:

raise Exception( 'Please use 3x3 or greater for compatibility '

'with 2.1' )

hosts, switches, dpid = {}, {}, 0

# Create and wire interior

for i in range( 0, x ):

for j in range( 0, y ):

loc = '%dx%d' % ( i + 1, j + 1 )

# dpid cannot be zero for OVS

dpid = ( i + 1 ) * 256 + ( j + 1 )

switch = switches[ i, j ] = self.addSwitch(

's' + loc, dpid='%016x' % dpid )

host = hosts[ i, j ] = self.addHost( 'h' + loc )

self.addLink( host, switch )

# Connect switches

for i in range( 0, x ):

for j in range( 0, y ):

sw1 = switches[ i, j ]

sw2 = switches[ i, ( j + 1 ) % y ]

sw3 = switches[ ( i + 1 ) % x, j ]

self.addLink( sw1, sw2 )

self.addLink( sw1, sw3 )

class LeafSpineTopo ( Topo ):

"""Leaf-Spine topology with a given leaf number, spine number and fanout"""

def build( self, leaf=2, spine=2, fanout=2):

self.dpid = 1

leaf_list, spine_list, hostNum = [], [], 1

# Build spine switches

self._addSwitch( spine, spine_list, "spine")

# Build leaf switches

self._addSwitch( leaf, leaf_list, "leaf")

# Link between leaf and spine

for spine_sw in spine_list:

for leaf_sw in leaf_list:

self.addLink(spine_sw, leaf_sw)

# Link between leaf and host

for leaf_sw in leaf_list:

for _ in range( fanout ):

host = self.addHost( 'h%s' % hostNum)

self.addLink( leaf_sw, host )

hostNum += 1

def _addSwitch( self, number, sw_list, sw_name ):

for i in range( 0, number ):

sw_list.append(self.addSwitch( '%s%s' % (sw_name, str(i + 1)), dpid='%016x' % self.dpid ))

self.dpid += 1

# pylint: enable=arguments-differ