bcmc 0.2.0

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bcmc is a CLI-centric IP broadcast and multicast tool built with Python. it is a testing tool for generating and validating broadcast or multicast traffic.

bcmc can be run as a server to generate broadcast or multicast traffic or bcmc can be run as a client to receive broadcast or multicast traffic. it is a CLI-based client/server tool inspired by iperf.

bcmc is developed by Josh Schmelzle and Kevin L. Marshall and is released under a three-clause BSD license.

requirements

bcmc requires Python 3.13 or newer. Python 2 support is dropped.

why bcmc?

Existing tools such as Multicast Hammer are platform specific and may have unsupported system dependencies on modern OSes. bcmc aims to be a free cross-platform tool that can be used from *unix or Windows. While bcmc aims to function cross-platform, please note some optional features may not work on certain OSes.

usage

bcmc is a client/server tool which functions similar to iperf. bcmc can be used to test and validate broadcast or multicast on 802.11 or 802.3 networks.

steps:

• You will need two hosts
• Place both hosts on the target test network
• Use one host to run bcmc in client mode (receive)
• Use the other host to run bcmc in server mode (transmit)

broadcast traffic

In broadcast mode, the default behavior for bcmc is to send IP layer UDP packets to 255.255.255.255.

multicast traffic

In multicast mode, the default behavior for bcmc is to send IP layer UDP packets to 239.0.0.2 as the multicast group address.

modes (-s|-c)

bcmc can be run as client or server.

traffic (-bc|-mc)

bcmc can generate broadcast or multicast IP packets.

broadcast (-bc)

client usage:

bcmc -c -bc

server usage:

bcmc -s -bc

multicast (-mc)

client usage:

bcmc -c -mc

server usage:

bcmc -s -mc

discovery tip

• to understand or "try out" the behavior of bcmc, you can also use bcmc with two different terminals on the same host.
• in one terminal, run bcmc in client mode
• in the other, run bcmc in server mode
• you should see incrementing messages from bcmc running in server mode in the terminal running bcmc as client mode.

troubleshooting

On Windows, bcmc server (-s) mode will default to the interface with the lowest metric. If you are having issues where client (-c) mode is not receiving messages from server (-s) mode, investigate the metric by running route PRINT from conhost (cmd.exe) or PowerShell.

optional arguments

usage: bcmc [-s|-c] [-bc|-mc] [options]
       bcmc [-h|--help] [-v|--version]

options:
  -h, --help            show this help message and exit
  -p 2002, --port 2002  port to listen on/connect to
  -b <host>, --bind <host>
                        bind to the interface associated with provided <host> address (experimental)
  --debug               increase output for debugging purposes
  -c, --client          run in client mode
  -s, --server          run in client mode
  -bc, --broadcast      set traffic type to broadcast
  -mc, --multicast      set traffic type to multicast
  --group 239.0.0.2     multicast group address (239.0.0.2 by default)
  -i 1, --interval 1    interval to send multicast packets
  --ttl 3               set the hop restriction in network for multicast server
  --dscp 46             set the Differentiated Service Code Point value applied to packets sent in server mode
  --padding 0           number of additional null bytes per payload which is sent in server mode
  --payload 'string'    add an arbitrary payload which is sent in server mode