py-mcast

• A simple python program to generate multicast traffic on a multicast address.
• Uses python sockets and argparse.
• Mainly for diagnostic purposes e.g. in a multicast lab.

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Developer Notes

conda create -n py-mcast
conda activate py-mcast
poetry install

If using VSCode SSH remote, change interpreter to conda env python path.

e.g. /home/usman/miniconda3/envs/py-mcast/bin/python3

Confirm with which python3

(network-automation) usman@dev-usman-lan:~/network-automation$ which python
/home/usman/miniconda3/envs/py-mcast/bin/python3

Usage

• Assuming a multicast capable network (PIM, IGMP, etc) is configured correctly:

  • On the publisher, run: python3 py-mcast.py publish -addr 239.1.1.1 -p 10000

  • And on the subscribers, run: python3 py-mcast.py subscribe -addr 239.1.1.1 -p 10000

  • Multiple publisher/subscribers can run on the same host, but each publisher/subscriber must have a unique UDP port number.

• Mcast group, port, ttl, interval and the message can be changed using the CLI arguments, remember to reflect change on both ends.

• Tested on a Linux hosts, but should work on Windows as well (might have to modify firewall).

• Set --interval as 0 to generate traffic continuously.

  • This generates ~20mbps of traffic.
  • Warning: this will cause a multicast storm if network isn't configured properly.

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Arguments for py-mcast.py

python3 py-mcast.py -h
usage: py-mcast [-h] [-addr MULTICAST_ADDRESS] [-p PORT] [-m MESSAGE] [-c COUNT] [-ttl TTL] [-ivl INTERVAL] job

A Python Multicast Traffic Generator.

positional arguments:
  job                   Action to do, publish or subscribe

options:
  -h, --help            show this help message and exit
  -addr MULTICAST_ADDRESS, --multicast-address MULTICAST_ADDRESS
                        multicast address to publish to
  -p PORT, --port PORT  port to publish to multicast packets on.
  -m MESSAGE, --message MESSAGE
                        message to multicast
  -c COUNT, --count COUNT
                        number of messages to send
  -ttl TTL, --ttl TTL   TTL of multicast packets .
  -ivl INTERVAL, --interval INTERVAL
                        Interval between multicast packets. 0 = 20mbps flood.

By <[email protected]> See https://blog.usman.network.

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Example