Sending Digests to a contoller

+--+      +--+     ++-+
|h1+------+s1+-----+h2+
+--+      +-++     +--+

Introduction

Similarly to the copy_to_cpu example in this example we show how to use the bmv2 digest extern to send information to the control plane using an out of band channel. In the digest we send a tuple with: (random_number, src_ip, dst_ip).

How to run

Run the topology:

sudo p4run

Run the very small controller code that receives packets from the switch:

sudo python get_digest.py

Any packet will trigger a digest so we can simply run a ping between h1 and h2, from the CLI

mininet> h1 ping h2 -c1