Notes: 1. Only file you need to modify is networking_application.py 2. In networking_application.py, look at the last function (main) first. 3. You will need to implement addHosts, addSwitches, addLinks, and networking_application functions in this file which get called in main. 4. Don't remove log messages (info(..)). Write relevant code immediately after the log message. 5. For the very first time "vagrant up" should take 10-12 minutes since it will need to download and install (1) ubuntu and (2) mininet However from next time it should run in less that a minute, unless you destroyed VM using "vagrant destroy". 6. When you execute "vagrant up" for the first time in the folder, there will be lot of warnings/errors (in red). Ignore them. 7. If in doubt, you can verify if "vagrant up" did everything it is supposed to do by logging into the guest VM and issuing following commands 1. which mn: It should show location of mininet executable 2. mn --version: It should show mn version (mininet version) 8. Once VM is up after first "vagrant up"; later you can use "vagrant provision" to just run networking_application.sh. Flow of Operations: 1. On vagrant up, Vagrantfile creates a VM of 1024MB RAM, 2 processor cores, Ubuntu 14.04 OS. and then calls bootstrap.sh 2. Bootstrap.sh installs mininet in the VM and calls networking_application.sh 3. Networking_application.sh should create three hosts(h1, h2, h3) and two switches(s1, s2) as per following topology s1-----s2 /\ | h1 h2 h3 4. Then h3 should ping to h1 and h2. 5. Normal case: when all links are working. 6. Fault 1: when h1-s1 link is down 7. Fault 2: when s1-s2 link is down