Cisco 3560 Interface Counters – Are Counters Reset Automatically?

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I have a Cisco 3560G switch. Are the interface counters reset automatically, recalculated in a specific interval (5 minutes?), or not at all?

I want to get (hourly, daily, monthly, etc) interface reports for the number of bytes passing through so I can charge a tenant a flat or proportional fee for the bandwidth they've used. I looked at my own interface and there's no way my int passed a paltry 5 GB ((inBytes+outBytes)/2^30) = ((3799659718+1574170392)/2^30). The counters are cleared at the first of the month (now = 2017-09-28 00:26); I regularly download ISOs and transfer many GB from the LAN file server.

Switch#sh int gx/y | i bytes
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     2661138970 packets input, 3799659718 bytes, 0 no buffer
     2963702247 packets output, 1574170392 bytes, 0 underruns

The above "packets input/output" lines are indented under the "5 minute output rate" line, so are the figures measured at 5 minute intervals?

Switch#sh int gx/y
...
  5 minute input rate 32000 bits/sec, 39 packets/sec
  5 minute output rate 39000 bits/sec, 44 packets/sec
     2661155241 packets input, 3801470626 bytes, 0 no buffer
     Received 232531495 broadcasts (0 multicast)
     0 runts, 8 giants, 0 throttles
     128 input errors, 50 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 7202264 multicast, 0 pause input
     0 input packets with dribble condition detected
     2963720601 packets output, 1576436851 bytes, 0 underruns
     0 output errors, 0 collisions, 7 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

Best Answer

Based on your comments, you are looking for the data usage over different time periods. You will need to use something like NetFlow or some other method to generate your reports.

The show interfaces command uses the interface load-interval <seconds> command to configure its time period. It defaults to 300 seconds 5 minutes, and it can be set from 30 to 600 seconds.

Note:

Bandwidth is how any raw bits you can push across a link in a given time period, usually measured in bps (bits per second). Throughput is how much usable data you can push across a link (basically, the bandwidth minus the protocol overhead), usually measured in Bps (bytes per second).

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