strange graphing issue

[cactifan]

Hi,
I just installed a fresh setup for cacti 0.8.6j and found a strange graphing issue with a 2.5Gbit/s POS link connected between two Cisco 7613.
Before creating any devices/graphs I modified the data source max value
inside the data template "Interface - Traffic" to deal with 1Gig/10Gig
interfaces by modifiying data sources 'traffic_in' and 'traffic_out' max values to '1250000000'.

After that I added the two devices and created graphs for a 2.5Gbit/s POS link connected between those two routers by using the 64bit snmp counters.

The link utilization is approx. 1.8Gbit/s peak in one direction, and approx. 220Mbit/s peak in the other.

the strange thing now is that the graph/port having the the 1.8Gbit/s as 'Inbound' (bottom in attached doc) is showing the graph correctly,
while the other graph where that traffic should show as 'Outbound"
(and should normally be identical to the other graph except that inbound and outbount is vice versa...) starts dropping around at 1.4Gbit/s and falls down to base line, and jumps up again if traffic is on the decreasing path falling below 1.4Gbit/s.

it seems that in the calculation for creating the 'outbound' line a
power of ten is somewhere missing when above 1.4Gbit/s ?

Some help or indication to look at is appreciated...

[gandalf]

Please compare data from "rrdtool info" of both the working and the not-working rrd file
Reinhard

[cactifan]

Hi Reinhard,

attached the output of rrdtool info.
The "not-working" info is in column A. The 'ds[traffic_out].value' in row 12
seems to have missing a power of ten ? (has +07, should have +08 like
ds[traffic_in].value in row 19/column B (the correct one) )?
Maybe an issue with the snmp agent in the box ?

Many thanks
Ralph

[gandalf]

At least there seems to be no error in the rrd file definitions. To verify your assumption, you will have to snmpwalk the failing device using well defined intervals and do math on your own to calculate throughput.
Reinhard

[cactifan]

Hi Reinhard,
it is the snmp agent of the box. I logged the snmp readings for the last 24hours and when the graph starts to jump the agent delivers wired values of the counters. So lets see what the Cisco TAC says...

thanks for the feedback anyway...

Ralph