In this section, we would be simulating a simple firewall that filters flow based on the destination IP address and the source IP address. For this, we will be using the single topology, which has three hosts, one switch, and one controller.
In this Net App, we will be utilizing the firewall application written in the Ryu controller directory. This can be found in the ryu/ryu/app/rest_firewall.py directory.
The topology is created using the following script:
<pre>ubuntu@sdnhubvm:~[13:29]$ sudo mn --topo single,3 --mac --switch ovsk,protocols=OpenFlow13 --controller remote –x
As stated earlier, this command creates a single topology with three hosts, one switch, and one controller. Also, the OpenFlow version is slated as 1.3 and the xterm to all the nodes will be opened.