Unable to contact the remote controller at 192.168.25.2:6633
*** Checking all Raspberry Pi
rpi2 rpi3 rpi4 rpi5 rpi6 rpi7 rpi8 rpi9 rpi10 rpi11 rpi12 rpi13 rpi14 rpi15 

*** Placing nodes on Raspberry Pi Cluster
h1:rpi2 h2:rpi3 s1:rpi2 s2:rpi3 

*** Creating network...
*** Adding controller
*** Adding hosts:
h1 h2 
*** Adding switches:
s1 s2 
*** Adding links:
(s1, h1) (s1, s2) (s2, h2) 
*** Configuring hosts
h1 h2 
*** Starting controller
c1 
*** Starting 2 switches
s1 s2 (rpi2)...(rpi3)...
*** Starting CLI:
*** CLI Started:
*** Ping: testing ping reachability
h1 -> h2 
h2 -> h1 
*** Results: 0% dropped (2/2 received)