Broadcast IP addresses and OpenC2

Last week, I attempted to start a discussion about OpenC2 and Broadcast.

I seem to have been too obscure, or not able to explain myself well, or something. This note describes the background of my comment and then raises the questions again.

Definitions:

In IPv4, we talk of CIDR range, and this comment discusses CIDR ranges. Class C ranges are the easiest to discuss, because they match the IP notation.

If I have the CIDR range 1.2.3.1/24, which means all 256 addresses from 1.2.3.0 to 1,2.3,255 are in the range. This comment is about the address 1.2.3.255, i.e., the highest address in each range, i.e., the broadcast address. It is called the broadcast address because all devices in the range 1.2.3.0, 1.2.3.1, ... 1.2,3,254 should receive and potentially respond to this address.

This is not just for 255 in a 24 bit mask. It applies to the top number in in CIDR range, where the remaining bits of the mask are replaced with all ones. There is a broadcast address for each CIDR range, no matter how small or large the range.

The Issue:

Is it legal to send an OpenC2 message to a broadcast address?

If it is legal, what should be the response of the Consumers>

openc2 message