README.md

Multicast Experiments

Make sure that your machine allows incoming traffic on port 5007:

sudo ufw allow 5007 udp

Run receiver.py to listen for incoming UDP Multicast packets.

Run sender.py to send UDP Multicast packets.

Docker

Run ./from-docker.sh to run sender.py inside a Docker container.

Dockerfile

FROM python:3.11-slim

WORKDIR /multi

COPY . .

CMD ["python", "./sender.py"]

from-docker.sh

docker build -t multicast_sender .

echo "Build done."
echo "Starting Container..."

docker run --rm --net host -it multicast_sender

receiver.py

#!/usr/bin/env python3

import socket
import struct


if __name__ == "__main__":
    multicast_group = ('224.1.1.1', 5007)

    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 5)
    sock.bind(multicast_group)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    group = socket.inet_aton(multicast_group[0])
    mreq = struct.pack('4sL', group, socket.INADDR_ANY)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)

    while True:
        received = sock.recv(1500)
        print(f'Received: {received.decode()}')

sender.py

#!/bin/bash

import socket
import time


if __name__ == "__main__":
    multicast_group = ('224.1.1.1', 5007)
    message = f'Sending from {socket.gethostname()}'

    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)

    while True:
        print(f'Sending message: "{message}"')
        sock.sendto(message.encode(), multicast_group)
        time.sleep(1)