mininet@mininet-vm:~$ sudo mn --topo single,2 --mac --switch ovsk --controller remote
 *** Creating network
 *** Adding controller
 Unable to contact the remote controller at 127.0.0.1:6633
 *** Adding hosts:
 h1 h2
 *** Adding switches:
 s1
 *** Adding links:
 (h1, s1) (h2, s1)
 *** Configuring hosts
 h1 h2
 *** Starting controller
 *** Starting 1 switches
 s1