Cacti Not Graphing correctly when Bandwidth reaches 110mb/s

[sa10]

If anyone can shed some light on why I am seeing this I would greatly appreaciate it.

I have 1 Foundry switch connected to a Juniper router running over a GiG-e link. At peek times the link reaches up to 130mb/s. Once it hits 110 - 114 mb/s it starts showing the traffic drop to under 10 megs. Here are 2 graphs, the first is one of the GIG-E Interface on the Switch, the Second is the GiGE interface on the Router.


as you can see, both are doing the same thing.
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I can watch the traffic real time and see that traffic is actaully flowing and there are no problems as cacti is reporting. I have verified that there are no rate limits on either interface. I have rebuild the graphs, tried changing the MAX Value in the DataSource. Still nothing seems to work.

I am monitoring multiple ports on each of these devices and I have no problems with any other graphs.

Any Help would be great
Thanks

[Guest]

It's not a cacti or rrdtool problem exactly.

The problem is that the SNMP counters that you are reading are 32bit values, and are rolling over within the 5 minute period, when you are reaching 114mbps.

You either need to upgrade your code (on the network device) to use 64 bit values, or run with a frequency of less than 5 minutes.

[sa10]

Thanks for the info.
I changed the poll time from every 5 min to every 3 min. Hopefully this will help.

Thanks.

I will post the results

[sa10]

Excellent,

That fixed the problem

Thanks for all your help.

John

[stoopinc]

I believe we are running into the same problem around the 190 mb mark. I have poller.php set tor un every three minutes in the crontab. Attached is the graph in question. You'll notice tha outbound all of the sudden drops.

[JoeNetwork]

The right way to fix it is to use SNMP v2c (a requirement), and 64-bit counters.

You may run into a snag where you device may or may not support SNMP v2c and/or 64-bit counters... but hopefully not.

[stoopinc]

I am currently using snmp v2 to query the Juniper. How do I make it use 64-bit counters?

[TheWitness]

From the pulldown. However, you may have to rename a bunch or old RRD files from the standard 64bit ones.

TheWitness

[gninja]

I had a bit of trouble getting this to work The Right Way with a Juniper Router, so I copied the graph templated and altered it to directly use an SNMP query.

The 64bit inbound counter for a juniper router (well, for mine at least) is:

1.3.6.1.4.1.2636.3.3.1.1.1.[index#]
outbound is:
1.3.6.1.4.1.2636.3.3.1.1.4.[index#]

You can figure out the index number for your interfaces through a verbose snmp interface query.