Check hostname is addressable

[beergeek]

Check that the hostname can be resolved CORRECTLY

[GeoffWilliams]

Interesting. Perhaps we could test this by going one better:
open listening sockets for all puppet ports (8140, 8142, 443, 61613, etc) and see if we can get data out the other end if we gethostbyname().

In a bash script I guess netcat would be good for this - in a 'real' program you'd be looking at the sockets library