A program built on this library only serves a device: usbip_device_plug() listens on TCP 3240 and nothing enumerates until the importing machine attaches it.

The importer is the USB/IP client - part of the OS, not of this library. (USB/IP inverts the words: the side providing the device is the server; see the role table.)

your program                        the client (importer)
USB device / USB-IP server   <---   USB host / USB-IP client   --->   OS USB stack
listens :3240                       connects                          binds a driver

The attach commands differ per OS - one page each:

Platform	Client	Attach with
Linux	built in (`vhci-hcd`)	`sudo usbip attach -r <ip> -b 1-1`
Windows	install `usbip-win2` / `usbip-win`	`usbip.exe attach -r <ip> -b 1-1`
macOS	none in-box; one experimental one (SIP off)	a hardware client, or drive from code
Hardware clients	importer firmware on a board	the board's own shell

On any OS you can also skip the client entirely: the host API imports and drives the device from your own process, with no kernel driver and no root. That is how the test suite runs, and one of the few options on macOS.

Whichever client you use: address the server as 127.0.0.1 when it is the same machine, otherwise by IP - and then serve on 0.0.0.0 so it is reachable (Going remote). The bus id is 1-1 unless you export several devices. Once attached, the OS binds its own in-box driver and the device is indistinguishable from real hardware.