Dear all,

I got a problem with a gigabit interface (module WS-X6148A-GE-TX on Catalyst 6506). Yesterday, the packet through this port was dropped. Here is the output of show interface command:

HND1-S6504-04#show int gigabitEthernet 3/24
GigabitEthernet3/24 is down, line protocol is down (notconnect)
  Hardware is C6k 1000Mb 802.3, address is 0018.741d.c880 (bia 0018.741d.c880)
  Description: **** Connect to ASA5540-04\G0/1 ****   chet
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Auto-duplex, Auto-speed
  input flow-control is off, output flow-control is desired
  Clock mode is auto
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 12:47:35, output hang never
  Last clearing of "show interface" counters 00:17:18
  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
  L2 Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast
  L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     23656714 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 7885570 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

I unplug this port and changed the connection to another port (G3/17) and the traffic was good.

It is so strange that I shut this port down but input errors and PAUSE output counter are still increase too fast (???)

For the Pause output, it was caused by the flow-control method of this interface, so I disabled output flow control and PAUSE output counter was stop.

But input error counter is still increase very fast.

So please tell me what makes the input error and PAUSE output on my interface even if it is shut down? Every other ports are still working normally, so I dont think there is an oversubscription here. Thank you very much.