verify_checksum

Verifying a checksum

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

Introduction

In this example we show how to verify IPv4 checksums and drop packets accordingly.

How to run

Start the topology:

sudo p4run

or

sudo python network.py

Start a receiver at h2:

mx h2
python receive.py

Send valid and invalid packets to h2 from h1:

mx h1
python send.py 10.0.1.2 valid/invalid

You will observe that only packets with a valid checksum get forwarded.