l2_learning

L2 Learning

+--+      +--+     ++-+
|h1+------+  +-----+h2+
+--+      +  +     +--+
          +s1+
+--+      +  +     ++-+
|h3+------+  +-----+h4+
+--+      +-++     +--+

Introduction

In this example you can see how to use copy to cpu or digests to implement a l2 learning P4 application and controller. You can find a better explained version of this example in the exercises section.

How to run

Copy-to-cpu-based L2 Learning

1. Start the topology (this will also compile and load the program).

   sudo p4run --conf p4app_cpu.json
   

   or

   sudo python network_cpu.py
   

2. Start the controller in another terminal window:

   sudo python l2_learning_controller.py s1 cpu

   We tell the controller from which switch listen from. The cpu parameter tells the controller which technique it should use to receive packets. In this case, sniffing an ethernet port.

Digest-based L2 Learning

1. Start the topology (this will also compile and load the program).

   sudo p4run --conf p4app_digest.json

   or

   sudo python network_digest.py

2. Start the controller in another terminal window:

   sudo python l2_learning_controller.py s1 digest

   We tell the controller from which switch listen from. The digest parameter tells the controller which technique it should use to receive packets. In this case it will use the nanomsg socket to receive digests.