P4 lab - Blackholing

The objective of this exercise is to write a P4 program that implements basic blackholing. After marking a port as blocked, switch will drop all traffic designated there.

Step 1: Implement basic blackholing

The black_hole.p4 file contains an implementation of the simplest forwarding, which switches all trafic from port 1 to port 2 and from port 2 to port 1. It also contains comments marked with TODO which indicate the functionality that you need to implement. A complete implementation of the black_hole.p4 switch will be able to to drop traffic for a given port.

Step 2: Run solution

1. In order to run a solution, run:

make run

2. After running the solution start HTTP server and try to fetch data from the other host. Request should complete successfully.

h2 python -m SimpleHTTPServer 8000 &
h1 wget 10.0.1.2:8000

3. Open another console, run simple_switch_CLI and connect to a switch:

simple_switch_CLI --thrift-port=9090

4. Add en entry in the blackholing table:

table_add blackholing blackhole_action 8000 =>

5. Try to fetch data from HTTP server again. It should fail.
6. Delete an entry from the table.

table_delete blackholing 0

7. HTTP server should operate back normally.