I'm thinking along the lines that the CDC Ethernet over USB (cdc_vnic_twrk70f120m) code should only pass traffic from USB to Ethernet and back and have no need for an IP address. But in the file "virtuial_nic_enet.h" there appears to be an IP address:
On Line 65 (or there abouts):
#define ENET_IPADDR IPADDR(169,254,3,3)/* Default IP Address */
Does this serve a purpose? Perhaps if I understand this I could better understand how the Freescale example works.