NVIDIA nForce Ethernet Controller (nvnet) is known network card in motherboards which are based on the NVIDIA nForce chipset. Also it's integrated in the original Xbox gaming console which is supported by ReactOS Xbox port.
Also nvnet is emulated by XQEMU: https://xqemu.com/networking/
This ticket basically clones old one
CORE-399, but includes more information for the actual implementation.
Hardware identifier: PCI\VEN_10DE&DEV_01C3
Existing code that can be helpful in the development of this driver: