[c-nsp] Packet Loss on 6513

Tue Apr 7 12:11:29 EDT 2009

We currently have 2 6513's in our core, and we have seen packet loss on our network. I was trying to locate the source of the packet loss. We did see some input queue drops on the SVI's and physical interfaces. I had increased our queue size on the vlan interfaces to 500, and our packet drops on the svi's decreased signifigantly. Now I am trying to figure out why there is packet loss on the physical interfaces. We have a sup 720, and our line cards are WS-X6724-SFP and WS-X6748-SFP.

Here is a sample of an interface with high drops
GigabitEthernet2/23 is up, line protocol is up (connected)
  Hardware is C6k 1000Mb 802.3, address is 001a.2f68.7bc2 (bia 001a.2f68.7bc2)
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 38/255, rxload 32/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is SX
  input flow-control is off, output flow-control is off
  Clock mode is auto
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:31, output hang never
  Last clearing of "show interface" counters 1d00h
  Input queue: 0/2000/91560/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 126671000 bits/sec, 28888 packets/sec
  5 minute output rate 151605000 bits/sec, 26499 packets/sec
     942611654 packets input, 633784740348 bytes, 0 no buffer
     Received 7319979 broadcasts (6903850 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 91560 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     891230426 packets output, 579042873963 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

I also looked at the utilization of this interface with our snmp tool, and utilixzation of this interface never went over %40

I also noticed the following, and was not sure if this was completely accurate:

show platform hardware capacity interface
Interface Resources
  Interface drops:
    Module    Total drops:    Tx            Rx      Highest drop port:  Tx  Rx
    1                          0           466                           0   1
    2                          0        154228                           0  23
    3                          0           123                           0   1
    4                          0        190102                           0  21
    5                          0        446318                           0  21
    7                 3940684041             0                           1   0
    9                          0         34280                           0   7
    10                         0             5                           0  42
    11                         0           433                           0  46
    12                         0          1686                           0  44
    13                     66042        119859                           1   1

  Interface buffer sizes:
    Module                            Bytes:     Tx buffer           Rx buffer
    1                                              1221120              152000
    2                                              1221120              152000
    3                                              1221120              152000
    4                                              1221120              152000
    5                                              1221120              152000
    6                                              1221120              152000
    9                                              1221120              152000
    10                                             1221120              152000
    11                                             1221120              152000
    12                                             1221120              152000
    13                                             1221120              152000

Does this mean that 3940684041 packets were dropped on the egress queue on the sup? Does this seem extremly high, and shat can cause this?
Thanks for your help

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