Massive readings from sub-interface

[ben987]

Hello,

I have a strange issue that is occurring on my cacti 1.2.9 servers, and also on my 0.8.8b server. Cacti is intermittently receiving massive readings from the router interface that aren't possible. Example shown below:

cacti.png (145.08 KiB) Viewed 1293 times

It is happening for subinterfaces of one interface only, on one router and is intermittent. When I check the SNMP readings directly from the router using snmpget, or by checking the counter directly, I never see numbers like this.
I am using 64 bit counters for these graphs, and I've tried re-adding the data sources/graphs, but this doesn't fix the problem.

How can I troubleshoot this issue, and has it been seen before?

Thanks,
Ben

[bmfmancini]

What hardware vendor is this ?