ExFogSim A framework to simulate distributed broker based federated fog computing environment
Step 1: Download and install omnet++ 4.6 (https://www.omnetpp.org/)
Step 2: Download Inet 3.6.4 (https://inet.omnetpp.org/) and import it as a project in omnet++
Step 3: Download mqttapp.zip from github (this project), extract it, and place it in following directory of Inet inet/applications/ (directory might no be same, just expand inet project, expand src, and then expand applications. This is the directory where you need to paste this mqttapp folder)
Step 4: Download exFogSim.zip extract it and import it as omnet++ project into omnet++
Step 5: Add Inet as reference in project
Go into testing or example folder of this newly created project and play with sample applications and example simulations.