# start mininet
sudo python fattree.py

# start pox controller
sudo ~/pox/pox.py forwarding.l2_learning \
  openflow.spanning_tree --no-flood --hold-down \
  log.level --DEBUG samples.pretty_log \
  openflow.discovery host_tracker \
  info.packet_dump

## in mininet CLI

  # test hosts
  >pingall
  >net
  >dpctl dump-ports-desc
  
  
  # link down
  
  >link s6 s13 down
  >link s11 s20 down
  >link s9 s15 down
  
# print all flowtable
./printflow.sh