• Start mininet with this simple config:

  $ sudo mn --topo single,3 --mac --switch ovsk --controller remote

• Start POX controller, using the rules in pox\misc\of_tutorial.py this:

  $./pox.py log.level --DEBUG misc.of_tutorial

  Change the path to run any other py file for controller.

• Open xterm for each host. In mininet console, type:

  xterm h1 h2 h3

• For host2 and host3, start tcpdump

  tcpdump -XX -n -i h2-eth0 replace (h2 )interface address with correct one for respective host, like h3 or h1

• Ping from host1 to others. Should be successful after 1st ping failure.

  ping -c1 10.0.0.x where x is number of dest host

• To open our topology

  sudo mn --custom ~/mininet/custom/our_topology.py --topo our_topology --mac --controller remote --arp

• To Start POX controller, using the rules in pox\forwarding\ourtop_learning.py this:

  $./pox.py log.level --DEBUG forwarding.ourtop_learning openflow.discovery openflow.spanning_tree --no-flood --hold-down

• To create a large file $ fallocate -l 100M 100Mfilename

##Steps to Implement the Routing Algorithm

• Run the Controller:

  $./pox.py log.level --WARNING forwarding.ourtop_learning openflow.discovery openflow.spanning_tree --no-flood --hold-down

• Run the Topology :

  sudo mn --custom ~/mininet/custom/our_topology.py --topo our_topology --mac --controller remote --arp --link tc

• Configure IP address to all the 3 Switches :

  sudo ifconfig switch1 10.0.0.252

  sudo ifconfig switch2 10.0.0.253

  sudo ifconfig switch3 10.0.0.254

• Add new Host:

  py net.addHost('h4')

• Add link between Switch and Host :

  py net.addLink(switch1, net.get('h4'))

• Attach the switch interface:

  py switch1.attach('switch1-eth7')

• Set the MAC address of the Host :

  py h4.intf('h4-eth0').setMAC('00:00:00:00:00:0d')

• Set the IP address of the Host:

  py h4.intf('h4-eth0').setIP('10.0.0.13/24')

Required Update the pox/proto/arp_responder.py file in the VM from the updated file in the repo

• Mininet:

  sudo mn --topo single,6 --mac --arp --controller remote

• POX: [LB IP addr we give here as 10.0.1.1, lb_dpid will be dpif of swtich on which LB runs]

  ./pox.py log.level --DEBUG misc.ip_loadbalancer --ip=10.0.1.1 --servers=10.0.0.1,10.0.0.2 --lb_dpid=3 Add following flags if topology has loops: openflow.discovery openflow.spanning_tree --no-flood --hold-down

• Start servers: [on h1/h2]

  python -m SimpleHTTPServer 80

• Do request: [on h3-h6] Request will go to LB's IP addr

  wget 10.0.1.1

How to run HTTP/FTP server on a host, and make it server requests from other hosts.

To run server in h1: Run in h1: python -m SimpleHTTPServer 80 or mininet> h1 (python cmd as above)

To download a file from h1: Run in h2: wget <serverip>/<filename> OR wget -O - 10.0.0.1 to get default server response on stdout

• 1 switch connected to multiple redundant servers, and multiple different client hosts
• 2 multiple switches connected in linear fashion (no loops)
• 3 multiple switches connected in ring (loop exists)
• 4 Make LB server-aware. So servers going down, or new ones coming up are supported !

Right now for the servers it knows, if some go down, it can handle that fine. Then if it 
goes up again that is handled. If a new server is to be serviced at this LB, that is not handled yet,
as the list of servers is provided in the beginning. Do we need this?? 

Think about the following questions:

• 3.a. Determine the cost of edges? Use bw, and delay parameter of links(TClinks)
• 3.b. L2 or L3 forwarding?
• 3.c. Subnets -> Same or Different?
• 3.d. Discovery of switches and hosts?
• 3.e. STP? Can use!
• 3.f. Changing of Bandwidth of the link - We could use by editing our topology file.

• integrate !

1. Task 1 - create a static flow table and test if forwarding work s- on our_topology .
2. Task 2 - add link costs and test.
3. Task 3 - Create link failure and check if re-routing is taking place.

dumps dumps all link info

links all link info

nodes node info

net for network info

<host>/<switch> arp -n Displays the ARP table of the host/switch ~~ The ARP table of the hosts is populated perfectly but not the switches

sudo ovs-ofctl show <switch> Displays all the links parameter including speed and status

arping -c 1 -I h1-eth0 h2 arpping dest h2 from h1.

• To Git clone

  git clone <web link of our repository> Make sure you do this in the directory you want your git

  You will have to add your unity id as username and its password when prompted

• To check status where your local repository stands in comparison to the online Git

  git status

• To add your file to your local git repsitory

  git add <filename>

• To committ

  git commit -m "Any comment on what your committed"

• To pull files/changes

  git pull -r

• To committ

  git push -u origin master Do this just first time, next time you can just 'git push'

Documentation https://openflow.stanford.edu/display/ONL/POX+Wiki#POXWiki-proto.arp_responder

servers = array of IPAddr(ip of each server)
ip = IPAddr object of LB ip addres

proto.arp_responder - util to learn and proxy ARPs

Objects/Classes providing API register on core, and then can be called with that name by others.

core.registerNew(iplb, event.connection, IPAddr(ip), servers)
# this registers iplb class, and passes the following 3 as parameters to class constructor.

LB remembers dpid of first switch to connect, and then provides LB on only that in future events, ignoring other switches. Attaches event listeners on the iplb object. Done.

do_expire :: to expire probes and memorized flows

do_probe :: sends an ARP to a server to see if it still alive

get a server to ping from `servers` list
make a new arp type ethernet packet by setting all required attributes. 	
add a timeout to the probe, store in dict of ip->timeout in `outstanding_probes`
send it out



on packetin event:
	get incoming port, and paket.parsed
	if tcp :
		if arp:
			if arp.reply type:
			then
				update the outstanding_probes dict
				update the live_servers dict - ignore if already found server, ADD if new server found.
				add as IP->mac,port to dict
	return drop packet if not tcp + arp (resends packet)

	if ip:
		if ip.srcip is known in servers list:
			extract key as srcip, dstip, srcport, dstport for TCP
			get entry from `memory`	
			   return drop packet (resends packet)

			refresh entry to reinstall it

		else if ip.dstip is loadbalancer's ip:
			~this packet needs to be LBed~
			extract key same as before, and get entry from memory for this key
			if entry is none, or entry.server not in live_Servers list:
				new possibly !
				pick server to send it to (LB strategy here! RR/WRR/random)
				create entry for it

			entry refresh/reinstall
			setup table entry towards seleced server
			setup actions, and create and install flowmod.

LOG.level CRITICAL ERROR WARNING INFO DEBUG

Mininet Walkthrough

How to identify different switches

Topology changes on-the-fly!