As you can see on the next picture, I have some links with throughput above 1,6Gbps.
On the link label I can see the correct value but in the graph something is wrong.
is it a bug?
With 30 second intervals you can record a maximum of about 1.5 gigabits/second while using 32 bit counters, I’d imagine that gap is right when the counter rolled over.
You could cut your polling interval in half to double the value you could graph. I have not seen it yet but I am sure I will some day. Our 10GB link between sites runs close to 1.5Gb.
thanks for your answer 
…but now I have two more questions:
-
the interval you talk about is the “probe interval”, ok? I have modified it to 20 seconds (I had this value in the label refresh interval)…
-
I’m using SNMPv2, so the counters are 64 bits, not?
many thanks
I have to say that changing the probe interval to 20 seconds doesn’t work
I was afraid that would happen, Just goes to show there is still more to learn.
SNMP v2 does not automatically give you 64 bit counters an as far as I can tell there is no way to get the dude to use 64bit counters with out building a custom probe… yuk. I have not seen a way to add a predefined link type that relies on the 64bit counters.
To take a guess at what is going on with the links, maybe they are forced to 30 seconds and ignore the probe interval.
As I said I currently don’t have any counters rolling over so I don’t have a good testbed for your trouble. And now I don’t know what to try since it seems that the probe interval for links is not tied to the global probe interval.
For your 10Gb links did you create a custom link type and specify the maximum 32 bit number? “4294967295”.
You will notice it will not allow you to place a higher number in the link.
If you snmp walk your device you will find High Capacity(HC) counters if it supports 64 bit counters. Start at this oid 1.3.6.1.2.1.31.1.1.1.6
There is a PDF from ipswitch that explains monitoring HC counters for whatsupgold from that PDF…
"This effect is evident in network interface utilization, where faster interface speeds cause 32-
bit counters to wrap so quickly that it is difficult to poll the counter frequently enough to not
miss a counter wrap.
Interface speed Time to wrap
10Mbs ~ 57 minutes
100Mbs ~ 5.7 minutes
Gigabit (1Gbs) ~ 34 seconds
High capacity counters alleviate this by substantially increasing the size of the counter: To
wrap a high capacity counter every 5 years, for example, would require an interface operating
at speeds of 1Tbs (1000Gbs)."
many thanks
so we have to wait until new releases…, I think imporant to upgrade the Dude counters because each day there are more 10GE links
Thanks for the Karma! I do hope they do support 64bit counters soon too!