In this section, we take the learning switch Net App and extend it to make packet forwarding decisions based on simple firewall rules that we install at the OpenFlow controller (POX). We are following two important goals in this Net App development. The first one is to demonstrate how easy it is to change the behavior of the network device (OpenFlow switch) by simply changing the Net App on the OpenFlow controller.
The second goal is to give more information about the POX controller. In our simple firewall Net App, we want the switch to make a drop or forwarding decisions based on the value of the source MAC address of the packets. The experimental network will be the one that is shown in the previous diagram. However, we augment the l2_learning.py Net App (L2 learning switch) to perform the functionality of a simple firewall. Therefore, we copy the l2_learning.py program with a new name (for instance, simple_firewall.py) and add the firewall logic and rules...