Cheshire Cat Computing

Had some network problems today, spanning-tree went a bit bonkers and induced a loop. I ended up with a 700mbit/s storm on my backbone links. When I go to look at the graphs, it shows 70 mbit/s. Here's the number straight from the interface:

717691000

The thing is that under normal traffic, like now, it is graphing correctly. The graph shows right at 7 mbit/s right now and the counter is 7062000. It looks like when I go over 100 mbit/s, it drops the least significant digit.

Am I missing something obvious in my configs? I've done MRTG since 1997, and am pretty familiar with the config options. Initially I considered adding a Factor = 10, but that would screw up the graphs, as they're fine at my normal workday speeds.

Thanks,

Richard

This is a known problem in MRTG. If your traffic exceeds 100Mb/s, you should be using 64-bit counters rather than the default 32-bit counters, else you get wrap occurring. Also, I think older versions of MRTG/perl resulted in a fixed length interger field, dropping off the first digit. This may be what's happenning here?

Steve

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

I'll have to look at setting the counters higher. Actually, it appears to be dropping the least significant digit, as the results would be right if they were multiplied by a factor of 10.