Simple Socket Server error //nios5.1sp1

my board use cyclone 1c12 and lan91c111(it like altera board ) ;test other use ok ,but net work too error ,use Simple Socket Server example ,display some error

nios2-terminal: connected to hardware target using JTAG UART on cable

nios2-terminal: "ByteBlasterII [LPT1]", device 1, instance 0

nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate)

Simple Socket Server starting up

Your Ethernet MAC address is 00:07:ed:ff:8f:11

[lwIP]: See STDERR for expanded diagnosis translation.

[lwIP]: [init_done_func] Fatal: lwip_devices_init failed, perhaps ethernet inter

face.

[lwIP]: ERRNO: :

[lwIP]: See STDERR (FAULT_LEVEL is SYSTEM).

[lwIP]: FAULT_LEVEL is SYSTEM.

[lwIP]: FATAL Error, Restart required.

[lwIP]: Locking scheduler - endless loop.

please help