I am getting massive input errors on my switch. Please see below. What could be causing this?

Posted on 2007-11-20
Last Modified: 2009-09-16
I am getting massive input errors on my switch. Please see below. What could be causing this? It is a 6509 cascaded with a 4506. We have just moved office and added the switches together. Vlan 10 is on it own switch 6509.

sh int vlan 10
Vlan10 is up, line protocol is up
  Hardware is EtherSVI, address is 001a.30b2.c400 (bia 001a.30b2.c400)
  Internet address is x.x.x.x/24
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 2/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 02:29:00
  Input queue: 2/75/2892085/2369823 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 10167000 bits/sec, 1568 packets/sec
  5 minute output rate 427000 bits/sec, 159 packets/sec
  L2 Switched: ucast: 33229836 pkt, 13922082204 bytes - mcast: 7452374 pkt, 7627649027 bytes
  L3 in Switched: ucast: 1397691 pkt, 228855426 bytes - mcast: 0 pkt, 0 bytes mcast
  L3 out Switched: ucast: 747574 pkt, 232406492 bytes mcast: 0 pkt, 0 bytes
     6027968 packets input, 4191690878 bytes, 0 no buffer
     Received 4568396 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 10902 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     809019 packets output, 237813721 bytes, 0 underruns
     0 output errors, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
Question by:colmbowler
LVL 16

Expert Comment

ID: 20324683

Could be something  as simple as a speed/duplex mismatch.  The 4500 works best "hard coded" rather then autosense.

Author Comment

ID: 20324742
The 4500 and 6509 are talking trough VLAN 20. There is no mismatch on VLAN 10. All are hard coded to 1000 Full
LVL 50

Expert Comment

by:Don Johnston
ID: 20324753
According to the Cisco output interpreter:

  WARNING: The input drop rate is greater than 1%.
  1. Paste the output of the 'show process cpu' command into the Output
     Interpreter to ensure that router is not overloaded.
  2. Determine whether the switching method of this interface can be improved. For
     example, use fast switching rather than process switching.
  3. Use the 'hold-queue in' interface
     configuration command to reduce the input queue size, and also to force input
  drops to become output drops.
  4. Submit the output of the show buffers command to the Output Interpreter
     to determine whether buffers need to be tuned.
  REFERENCE: For more information, see Troubleshooting Input Drops
  INFO: 2369823 flushes have been recorded for this interface.
  Flushes are similar to input drops, but are proactively forced by the router before
  the input queue is full. Selective Packet Discard (SPD) is the congestion avoidance
  mechanism used, where non-control packets are dropped in preference to control
  packets (i.e. routing updates). Monitor the number of flushes. If they continue
  to increment, try to increase the size of the input queue and/or improve the
  switching mechanism used by this interface (for example, change process switching
  to fast switching). You can troubleshoot flushes in a manner similar to input
  REFERENCE: For more information, see Troubleshooting Input Drops.
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Author Comment

ID: 20324858
fair enough . Here is the output interprter for sh process cpu

Results listed by "show" commands
The following hyperlinks are headings for the supported commands that you
submitted. Each hyperlink takes you to the relevant section within the analysis results.


Back to top

ERROR: No Error message was found.
TRY THIS: Ensure that the error message has the following format:
Some examples would be:
Resubmit the output as necessary.

Back to top

INFO: Total CPU Utilization is comprised of process and interrupt percentages.
  Total CPU Utilization: 28%
  Process Utilization: 11%
  Interrupt Utilization: 17%
These values are found on the first line of the output:
 CPU utilization for five seconds: x%/y%; one minute: a%; five minutes: b%
  Total CPU Utilization: x%
  Process Utilization: (x - y)%
  Interrupt Utilization: y%
Process Utilization is the difference between the Total and Interrupt (x and y).
The one and five minute utilizations are exponentially decayed averages (rather
than an arithmetic average), therefore recent values have more influence on the
calculated average.

INFO: Total CPU Utilization is 28% for the past 5 seconds.
INFO: Total CPU Utilization is 24% for the past 5 minutes.
NOTE: This is an exponentially decayed average rather than an arithmetic average,
therefore recent events have a greater effect than past events.
Compare this CPU value to the baseline or average utilization. If a baseline is
not available, create one by collecting 'show process cpu' outputs during the course
of several days. If available, use the 'show process cpu history' command (available
in IOS 12.2 and higher).
The following processes are causing excessive CPU usage:
 PID      CPU Time      Process
ERROR: No Processes were found having a CPU utilization greater than 10%
NOTE: If there are processes with a utilization greater than 10%, ensure that
there is no line wrapping as this will interfere with the analysis.
REFERENCE: For troubleshooting information, please visit Troubleshooting High
CPU Utilization on Cisco Routers

Expert Comment

ID: 21035927
we have the same issue during backups, using a product called eVault.  DId you find a resolution?

Accepted Solution

colmbowler earned 0 total points
ID: 21036725
No not yet. Trying to reduce traffic on the vlans but it is a nightmare trying to find the problem I f i find anything I will let you know . Visa -versa

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