SDN 101: Practical example for SDN Controller

What is software-defined networking (SDN) by practical example?

Requirement:
1- HP VAN SDN Controller.
2- Mininet emulation build openflow switches
3- Python HP SDK for build routing protocol

1- How to  Build Topology?

Topology appear on SDN Controller after running Topology.py script.

Using Mininet Emulation openflow switch:
using python for draw topology:

Topology.py
===================================
"""Custom topology example


Adding the 'topos' dict with a key/value pair to generate our newly defined
topology enables one to pass in '--topo=mytopo' from the command line.
"""

from mininet.topo import Topo

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

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

        # Initialize topology
        Topo.__init__( self )

        h1 = self.addHost( 'h1', ip='10.10.2.1/24', defaultRoute='via 10.10.2.254' )
        h2 = self.addHost( 'h2', ip='10.10.2.2/24', defaultRoute='via 10.10.2.254' )
        h3 = self.addHost( 'h3', ip='10.10.2.3/24', defaultRoute='via 10.10.2.254' )
        h4 = self.addHost( 'h4', ip='10.10.2.4/24', defaultRoute='via 10.10.2.254' )
        h5 = self.addHost( 'h5', ip='10.10.2.5/24', defaultRoute='via 10.10.2.254' )
        h6 = self.addHost( 'h6', ip='10.10.2.6/24', defaultRoute='via 10.10.2.254' )
        g1 = self.addHost( 'g1', ip='10.10.2.254/24')
     
        s1 = self.addSwitch( 's1', dpid='0000000000000001',protocols='OpenFlow13' )
        s2 = self.addSwitch( 's2', dpid='0000000000000002',protocols='OpenFlow13' )
        s3 = self.addSwitch( 's3', dpid='0000000000000003',protocols='OpenFlow13' )
        s4 = self.addSwitch( 's4', dpid='0000000000000004',protocols='OpenFlow10' )
        s5 = self.addSwitch( 's5', dpid='0000000000000005',protocols='OpenFlow13' )
        s6 = self.addSwitch( 's6', dpid='0000000000000006',protocols='OpenFlow13' )

        #core
        self.addLink ( s1, s2 )

        #distribution
        self.addLink ( s1, s3 )
        self.addLink ( s1, s4 )
        self.addLink ( s1, s5 )
        self.addLink ( s1, s6 )

        self.addLink ( s2, s3 )
        self.addLink ( s2, s4 )
        self.addLink ( s2, s5 )
        self.addLink ( s2, s6 )

        #acccess
        self.addLink( s3, h1 )
        self.addLink( s3, h2 )
        self.addLink( s4, h3 )
        self.addLink( s4, h4 )
        self.addLink( s5, h5 )
        self.addLink( s5, h6 )
        self.addLink( s6, g1)

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

"""
#
how to run:
sudo mn --custom topology.py --topo mytopo --controller=remote,ip=10.0.0.11
"""

=============================================================

2- How to build routing protocol?

for example:
I need choose the best route between PC 10.10.2.254   to Server 10.10.2.1
i choose this pass as the best route:
H1(10.10.2.254) ---- S3 ---- S2----- S1-----S6 ------G1(10.10.2.1)

Write script called Route.py
=================================================
#!/usr/bin/env python
#
#    traffic route between H1 TO G1 Server
# H1 ---- S3 ---- S2----- S1-----S6 ------G1
# 


import hpsdnclient as hp

def main():
    #initialize the api
    controller = '192.168.79.131'
    auth = hp.XAuthToken(user='sdn', password='skyline', server=controller)
    api = hp.Api(controller=controller, auth=auth)

    #create the match object
    match = hp.datatypes.Match(eth_type="ipv4", ipv4_src="10.10.2.1",
                               ipv4_dst="10.10.2.254",ip_proto="tcp",
                               tcp_dst="80")

    #create the action objects
    output1 = hp.datatypes.Action(output=1)
    output2 = hp.datatypes.Action(output=2)
    output3 = hp.datatypes.Action(output=3)
    output5 = hp.datatypes.Action(output=5)

    #create the flows
    flow1 = hp.datatypes.Flow(priority=30000, idle_timeout=300,
                              match=match, actions=output5)
    flow2 = hp.datatypes.Flow(priority=30000, idle_timeout=300,
                              match=match, actions=output1)
    flow3 = hp.datatypes.Flow(priority=30000, idle_timeout=300,
                              match=match, actions=output2)
    flow6 = hp.datatypes.Flow(priority=30000, idle_timeout=300,
                              match=match, actions=output3)


    #push the flows to the datatpaths
    api.add_flows('00:00:00:00:00:00:00:03', flow3)
    api.add_flows('00:00:00:00:00:00:00:02', flow2)
    api.add_flows('00:00:00:00:00:00:00:01', flow1)
    api.add_flows('00:00:00:00:00:00:00:06', flow6)

if __name__ == "__main__":
    main()

======================================================

After running script can be on SDN controller path as red line like above Image.


Good Luck