Hello Dude,
For a local publish broker connectivity is not needed. IS just acts as a broker. For more info. refer pub-sub guide.
Follow the steps:
Create a document say localDoc and add a string message and make it publishable (make sure IS is not connected to broker)
Create a subscribing service (add a debugLog and write some message) and create a trigger as usual
Run the publishable document directly and do a local publish or you can use publish BIS.
Let me know if you still face issues.
#Integration-Server-and-ESB#broker#webMethods#Universal-Messaging-Broker