Hi anykey, 
Danke für Deine Antwort und hier die Config auf interface 0: 
  
router>show interface fast 0 
FastEthernet0 is up, line protocol is down 
  Hardware is PQUICC_FEC, address is 0012.dac3.c8eb (bia 0012.dac3.c8eb) 
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, 
     reliability 135/255, txload 1/255, rxload 1/255 
  Encapsulation ARPA, loopback not set 
  Keepalive set (10 sec) 
  Auto-duplex, Unknown Speed, 100BaseTX/FX 
  ARP type: ARPA, ARP Timeout 04:00:00 
  Last input never, output 00:00:00, output hang never 
  Last clearing of "show interface" counters never 
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 
  Queueing strategy: fifo 
  Output queue: 0/40 (size/max) 
  5 minute input rate 0 bits/sec, 0 packets/sec 
  5 minute output rate 0 bits/sec, 0 packets/sec 
     0 packets input, 0 bytes 
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 
     0 watchdog 
     0 input packets with dribble condition detected 
     86 packets output, 5160 bytes, 0 underruns 
     86 output errors, 0 collisions, 2 interface resets 
     0 babbles, 0 late collision, 0 deferred 
     86 lost carrier, 0 no carrier 
     0 output buffer failures, 0 output buffers swapped out