Mininet script for multiple controllers

Controller 1 is running on 192.168.200.22
Controller 2 is running on the same machine that mininet is running

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

#!/usr/bin/python

from mininet.net import Mininet
from mininet.node import Controller, OVSKernelSwitch, RemoteController
from mininet.cli import CLI
from mininet.log import setLogLevel, info

def emptyNet():

    net = Mininet(controller=RemoteController, switch=OVSKernelSwitch)

    c1 = net.addController('c1', controller=RemoteController, ip="192.168.200.22", port=6633)
    c2 = net.addController('c2', controller=RemoteController, ip="127.0.0.1", port=6633)

    h1 = net.addHost( 'h1', ip='10.0.0.1' )
    h2 = net.addHost( 'h2', ip='10.0.0.2' )
    h3 = net.addHost( 'h3', ip='10.0.0.3' )
    h4 = net.addHost( 'h4', ip='10.0.0.4' )

    s1 = net.addSwitch( 's1' )
    s2 = net.addSwitch( 's2' )

    s1.linkTo( h1 )
    s1.linkTo( h2 )
    s1.linkTo( s2 )
    s2.linkTo( h3 )
    s2.linkTo( h4 )

    net.build()
    c1.start()
    c2.start()
    s1.start([c1,c2])
    s2.start([c1,c2])

    net.start()
    net.staticArp()
    CLI( net )
    net.stop()

if __name__ == '__main__':
    setLogLevel( 'info' )
    emptyNet()

In band controller

SDN Can be deployed in two ways..

Out Band Control : All the switches are directly connected to controller. So controller traffic go via the directly connected links.

s1 ---  s2 --- s3
 l         l       l
 l ----- c1----- l

In Band Control : A switch is connected to the controller via another switch

s1 --- s2
 l
c1


#!/usr/bin/python

from mininet.net import Mininet
from mininet.node import RemoteController, OVSSwitch
from mininet.cli import CLI
from mininet.log import setLogLevel, info

class InbandController( RemoteController ):

    def checkListening( self ):
        "Overridden to do nothing."
        return

def emptyNet():

    "Create an empty network and add nodes to it."

    net = Mininet( topo=None, build=False)

    net.addController('c0', controller=InbandController, ip='10.0.0.1')

    h1 = net.addHost( 'h1', ip='10.0.0.1' )
    h2 = net.addHost( 'h2', ip='10.0.0.2' )
    h3 = net.addHost( 'h3', ip='10.0.0.3' )

    s1 = net.addSwitch( 's1', cls=OVSSwitch )

    net.addLink( h1, s1 )
    net.addLink( h2, s1 )
    net.addLink( h3, s1 )

    net.start()
    s1.cmd('ifconfig s1 10.0.0.10')

    CLI( net )
    net.stop()

if __name__ == '__main__':
    setLogLevel( 'info' )
    emptyNet()

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We start the controller in h1..

So start the controller.  First open an xterm to h1, which is where we said the controller would be.

mininet> xterm h1

When the xterm opens, start the controller. For this quick test, we will just start the OpenFlow Reference controller.

root@mininet-vm:~# controller -v ptcp:6633

This means that the controller and switch are successfully talking to each other.  And if you do a pingall now.

mininet> pingall
*** Ping: testing ping reachability
h1 -> h2 h3
h2 -> h1 h3
h3 -> h1 h2
*** Results: 0% dropped (6/6 received)

Switch / Link go down and come up on the fly

It is detected by openflow.discovery

s1 goes down and comes up

mininet > py s1.stop

mininet > py s1.start([c1,c2])

Add components to mininet on fly

Add a new controller, switch, two hosts

mininet> py net.addController('c2', IP="127.0.0.2", port=6633)

mininet> py net.addSwitch('s2')
mininet> py s2.start([c2])

mininet> py net.addHost('h4')
mininet> py net.addLink(s2, net.get('h4'))
mininet> py s2.attach('s2-eth1')
mininet> py net.get('h4').cmd('ifconfig h4-eth0 10.4')

mininet> py net.addHost('h5')
mininet> py net.addLink(s2, net.get('h5'))
mininet> py s2.attach('s2-eth2')
mininet> py net.get('h5').cmd('ifconfig h5-eth0 10.5')

Multiple controllers and Mininet on the same VM

1) Mininet Script

c1 = net.addController('c1', controller=RemoteController, ip="127.0.0.2", port=6633)

c2 = net.addController('c2', controller=RemoteController, ip="127.0.0.1", port=6634)

2) Start POX controllers

./pox.py --port=6633 MyScript.py

./pox.py --port=6634 MyScript.py

Configure openVswitch with POX controller

Configure openVswitch in openVswitch in PC1

PC1 eth0.10 interface IP is 192.168.10.100

#We attach  PC1 eth0.10 interface to the bridge connection between openVswitch in PC1 and controller

$sudo ovs-vsctl add-br br0
$sudo ovs-vsctl add-port br0 eth0.10
$sudo ifconfig br0 192.168.10.100 netmask 255.255.255.0

#Attach OpenvSwitch to the Controller which is in 192.168.100.30

$ovs-vsctl set-controller br0 tcp:192.168.100.30:6633

To remove openVswitch bridge connection

$sudo ovs-vsctl del-br br-0
$sudo ovs-vsctl del-port br-0 eth0.10

To remove the Controller

$sudo ovs-vsctl del-controller br-0

Installing and Configuring OpenVSwitch on Ubuntu 12.10

System Preperation

Install dependencies

$apt-get update 

$apt-get install python-simplejson automake autoconf gcc uml-utilities libtool build-essential git pkg-config

Download the OVS tarball Note: you can also pull from the git repository 

$wget http://openvswitch.org/releases/openvswitch-1.10.0.tar.gz

$tar zxvf openvswitch-1.10.0.tar.gz

$cd openvswitch-1.10.0

Compiling Open vSwitch From Source 

$./boot.sh   

$./configure --with-linux=/lib/modules/`uname -r`/build 

$make 

$make install

#Load the OVS Kernel Module

$insmod datapath/linux/openvswitch.ko

#Pull down the headers for your kernel

$sudo apt-get install linux-headers-`uname -r`

Open vSwitch Configuration 

$touch /usr/local/etc/ovs-vswitchd.conf 

$mkdir -p /usr/local/etc/openvswitch 

$ovsdb-tool create /usr/local/etc/openvswitch/conf.db vswitchd/vswitch.ovsschema

#Start ovsdb-server, this stores the config into a file that is persistent even after restarts.

$ovsdb-server /usr/local/etc/openvswitch/conf.db \

--remote=punix:/usr/local/var/run/openvswitch/db.sock \

--remote=db:Open_vSwitch,manager_options \

--private-key=db:SSL,private_key \

--certificate=db:SSL,certificate \

--bootstrap-ca-cert=db:SSL,ca_cert --pidfile --detach --log-file

#Only need to run this the first time. 

$ovs-vsctl --no-wait init

#Start vswitch  

$ovs-vswitchd --pidfile --detach

#Verify the kernel module(s) in case you didn't earlier and get errors. 

$lsmod | grep br 

brcompat               13512  0

openvswitch            98196  1 brcompat

#If they are not there try loading again and check your path to the kernel module. 

$insmod datapath/linux/openvswitch.ko

#At this point you have a fucntioning vanilla OVS install. Output should look something like this. 

$ovs-vsctl show

b6d574d7-5582-4cc0-93e5-a90cf0eb0a38

root@demo-139:/home/ubuntu/ovs-vxlan# ovs-vsctl --version

ovs-vsctl (Open vSwitch) 1.8.90

Compiled October 03 2013 06:23:36