Follow the following steps to setup the OpenFlow switch

1. Download openvswitch

   wget http://openvswitch.org/releases/openvswitch-2.5.2.tar.gz
   

2. Unpack archive

   tar -xvzf openvswitch-2.5.2.tar.gz
   

3. Install following dependancies

   apt-get install python-simplejson python-qt4 libssl-dev python-twisted-conch automake autoconf gcc uml-utilities libtool build-essential pkg-config
   apt-get install linux-headers-3.10-3-rpi
   

4. Make the switch (Navigate to openvswitch-2.5.2 and enter the following commands)

   ./configure --with-linux=/lib/modules/3.10-3-rpi/build
   make
   make install
   

5. Turn on openvswitch module

   cd openvswitch-2.5.2/datapath/linux
   modprobe openvswitch
   

6. Create ovs_script.sh with the following code
   

   #!/bin/bash
   ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock \
    --remote=db:Open_vSwitch,Open_vSwitch,manager_options \
    --private-key=db:Open_vSwitch,SSL,private_key \
    --certificate=db:Open_vSwitch,SSL,certificate \
    --bootstrap-ca-cert=db:Open_vSwitch,SSL,ca_cert \
    --pidfile –detach
   ovs-vsctl --no-wait init
   ovs-vswitchd --pidfile –detach
   ovs-vsctl show
   

7. Create a file for the database, which will contain the details of the switch

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

8. Create the following directory

   mkdir -p /usr/local/etc/openvswitch
   

9. Populate the database, which will be used by the ovswitch

   ./openvswitch-2.5.2/ovsdb/ovsdb-tool create /usr/local/etc/openvswitch/conf.db openvswitch-2.5.2/vswitchd/vswitch.ovsschema
   

10. Run ovs_script.sh

11. Add a new bridge

    ovs-vsctl add-br br0
    

12. Bind the ports to the newly added bridge

    ifconfig eth1 0 up
    ifconfig eth2 0 up
    ifconfig eth3 0 up
    ifconfig eth4 0 up
    

13. Set the interfaces up

    ifconfig eth1 0 up
    ifconfig eth2 0 up
    ifconfig eth3 0 up
    ifconfig eth4 0 up
    

14. Connect the switch to an external controller

    ovs-vsctl set-controller br0 tcp:20.0.0.7:6634
    

Configuring the switch to initialize as an OpenFlow switch at startup

• Add the following bash script to the location of openvswitch-2.5.2 and rename it to main_script.sh

  #!/bin/bash
  cd openvswitch-2.5.2/datapath/linux
  modprobe openvswitch
  cd ..
  cd ..
  cd ..
  ./ovs_script.sh
  ifconfig eth1 0 up
  ifconfig eth2 0 up
  ifconfig eth3 0 up
  ifconfig eth4 0 up
  ifconfig br0 0 up
  

• Then add the following line at the end of .bashrc

  sudo sh [location of main_script.sh]/main_script.sh
  

Extracting the hex value of DPID in a convenient way

• Add the following file to an arbitrary location and rename it to dpid.sh

  #!/bin/bash
  var=$(cat /sys/class/net/br0/address)
  output=$(echo "$var" | tr --delete :)
  echo "DPID : " $((0x${output}))
  

• Then run the above script using the following command

  sh dpid.sh