If porting a system with two NICs installed, but only one in use, the Dummy network option can be used to define a NIC to the emulator to retain the existing system's network configuration.  For example, if a system has NICs EWA and EWB defined, but only EWB is used, EWA can be assigned to Dummy network while EWB is assigned to a host NIC.  The original Alpha configuration is thus preserved, which may negate the necessity of updating the VMS network configuration.