MRTG shows 100 Mbps peaks after "clear counters" on GE and 10GE ports

[human]

On several types of switches, "clear counters" resets all SNMP counters to zero.

However, MRTG does not handle this situation correctly when 64-bit counters are used.

The problem is in rateup.c:

              if (outr < 0)     /* wrapped 32-bit counter? */
                outr += (long long) 1 << 32;

This code assumes couters are always 32-bit. But for GE and 10GE interfaces, where 64-bit counters are inevitable, the above code performs wrong computation and creates 100 Mbps peaks in graphs

[oetiker]

thanks for the report. Fix is in r322.