mrtg peak on reboot / snmp-issue?

[Hartmut Brandt]

Olivier Mueller wrote:
> Hello,
> 
> Small but curious thing on my freebsd-based systems: when a
> server is rebooted, it generates a peak (or "spike"?) on the
> network mrtg for all interfaces (here just before 1 am): 
> http://8304.ch/om/stuff/mrtg_localhost_1-day.png

This could happen if either the daemon fails to correctly provide 
ifCounterDiscontinuityTime or mrtg fails to correctly interpret 
sysUpTime and/or ifCounterDiscontinuityTime.

> It happens with both net-snmp and ucd-snmp, with a quite standard 
> mrtg installation (generated by cfgmaker). 
> 
> Do you have the same "issue" on your own servers?  All I can add, is
> that there is not such a high traffic after a reboot, and that it
> doesn't happen on similar linux-based systems.


harti