Where the vmnet default network subnet 192.168.64.1/24 is documented?

[nirs]

The Technical overview mentions:

Normally, vmnet creates the container network using the CIDR address 192.168.64.1/24, and on macOS 15, container defaults to using this CIDR address in the network helper.

I could not find this in vmnet documentation or headers, and the source is not available.

Testing creation of vment_network_ref shows that the network we get depends on the user:

• root: 192.168.2.1/24
• unprivileged user: 192.168.64.1/24

I wonder if this behavior is documented somewhere. I'm working on a tool to manage vment_network_ref, and it will be useful if the tool do not conflict with the containers network.

I'm asking here since vmnet is not open source and has no effective discussion space.

[jglogan]

The subnet assignment policy vmnet implements is completely undocumented.

If you're using the new vmnet APIs (which are only present on Tahoe) for creating networks, your best bet is to default to what container does - let vmnet choose the subnet, and use the APIs to determine what subnet you got after creation.