debugging packet loss

Tue Jul 23 15:53:29 UTC 2002

I'm seeing 2-5% packet loss going through a Cisco 2621 with <10mbps of
traffic running at ~50% CPU.  (packet loss based on ping results)

Pinging another box on the same catalyst 2900 switch gives no packet loss,
so it seems the 2621 is the source of the packet loss.  I need help
figuring out why it is dropping packets, and how to stop it.

The odd thing is that the interface stats don't show any dropped packets:
  Full-duplex, 100Mb/s, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 00:01:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 00:10:16
  Queueing strategy: fifo
  Output queue 0/40, 0 drops; input queue 1/512, 0 drops
  5 minute input rate 5257000 bits/sec, 1383 packets/sec
  5 minute output rate 5692000 bits/sec, 1448 packets/sec
     845743 packets input, 392733148 bytes
     Received 403 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast
     0 input packets with dribble condition detected
     887446 packets output, 430245866 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 22694 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

Ralph Doncaster
principal, IStop.com 