The present invention relates generally to a data communication system, a virtual interworking trunk interface within a device to form a universal virtual private network, and methods of operating a virtual private network. In a particular embodiment, the data communication system includes a first portion of a virtual private network, a second portion of the virtual private network, a virtual switch instance associated with the first portion of the virtual private network, a virtual router instance associated with the second portion of the virtual private network, and a virtual interworking trunk interface coupled to the virtual switch instance and to the virtual router instance.