First thing to do when you have issues connecting to Iguana is to see if Iguana is running and if the web port is open. Try using a tool like wget or curl.
To access the web interface of Iguana from outside of the machine it is running on then you will often need to configure what TCP/IP ports are open on the machine to access through the public IP address of the machine.
We give an example workflow doing this with an EC2 instance on Amazon webservices.