3 Replies Latest reply on Aug 16, 2010 12:48 PM by jswan

    large discrepancy between NetFlow and SNMP statistics

    jswan

      I just did the following for one of my WAN interfaces:

      1) Custom "bytes transmitted/received" report for 8/9/10 0900h to 8/10/10 0900h, using a 15 minute sample interval. Then I downloaded the raw data and summed the "received" column in Excel. I got approximately 5.1 GB.

      2) Custom Netflow report for the same interface, same time period, with "ingress" selected. I then summed the values for TCP, UDP, EIGRP, and ICMP and got 2.85 GB.

      This is a huge discrepancy that can't be explained by stuff like protocol overhead or layer 2 traffic (the only layer 2 traffic on this interface is CDP and serial keepalives).

      Any idea what might be going on here?