[5.1] pflow(4) flow with starttime *after* endtime

[Patrick Lamaiziere]

Hello,

We have just noticed that pflow (v5) sometime (but often) uses a
StartTime value which is later than the EndTime.
So the duration is interpreted 4294966.296000000 secondes.
This confuses our collector (nfsen).

(wireshark)
   pdu 19/30
        SrcAddr: 194.57.169.116 (194.57.169.116)
        DstAddr: 129.20.254.1 (129.20.254.1)
        NextHop: 0.0.0.0 (0.0.0.0)
        InputInt: 0
        OutputInt: 0
        Packets: 3
        Octets: 164
        [Duration: 4294966.296000000 seconds]
            StartTime: 251367.000000000 seconds
            EndTime: 251366.000000000 seconds
        SrcPort: 55680
        DstPort: 53
        padding
        TCP Flags: 0x00
        Protocol: 6
        IP ToS: 0x00
        SrcAS: 0
        DstAS: 0
        SrcMask: 0 (prefix: 194.57.169.116/32)
        DstMask: 0 (prefix: 129.20.254.1/32)
        padding

Any clue?
Thanks, regards.