What you pass to setDomain will be set as the "document.domain" property
of the page. Hence, it must obey the restrictions browsers pose on this property.
As far as we know, using an IP address is never allowed.
You cannot have a Web Server and Lightstreamer Server interoperate if you
access them through ip addresses.

As long as you are just testing, we suggest leveraging the "hosts" file of you client machine and assigning fake hostnames to the machines which run the Web Server and Lightstreamer Server.