Final Word on Allow 64 bit counters?

riffster

I have read the various threads on issues pertaining to allowing 64 bit counters to be used in gathering statistics from SNMP OIDs.

The Orion Administrator Guide seems to come down squarely on both sides of the equation:

If you have high-speed interfaces and you are experiencing frequent counter rollovers, you may wish to enable 64-bit counters. Confirm that the monitored device supports 64-bit counters and check the Allow 64-bit Counters checkbox in the Node Details window. Note: Some vendor implementations of 64-bit counters produce faulty data. If you are experiencing erratic or incorrect data, you may wish to disable 64-bit counters by unchecking Allow 64 bit counters.

My hand-wringing over this subject has been occasioned by the discovery that statistics were not being produced by (too) many of our routers in our 10.7 SLX version of Orion NPM. It turned out that these routers (it appears that the 2900 series, and specifically the 2911 series) had the "Allow 64 bit counters" box checked during installation. As a result it turned out that allowing these 64 bit counters killed statistics collection from PPP interfaces in particular - so we had to remove that box in order to correctly collect statistics from boxes with PPP (and sometimes other larger bandwidth interfaces it seems.)

What is the rule of thumb here on whether or not to check or not check that box during node installation? I don't want nodes to have no statistics collection, but on the other hand couldn't it well be that there will be issues in other scenarios in which 64 bit counters are not allowed?

Or is there no rule of thumb and only testing and observation can suffice to say whether the 'Allow 64 bit counter' box should be checked?

sean.martinez

If your Interfaces are 200Mb or higher, it is recommended to enable and allow 64 bit counters.

1Gb Interfaces at max utilization will achieve counter wrap at 3 minutes. The default NPM polling for Interfaces is every 9 minutes to determine the delta of the previous counter to the current counter. This counter wrap will report the interface utilization incorrectly by showing very high above 100% or very low when this occurs.

If the Interface is showing the utilization incorrectly, I always recommend to check to make sure that the bandwidth is correct (sometimes the device has a bug which reports the interface incorrectly) and whether the Interface has 64 bit counters enabled. Some older devices will not support 64 bit counters, but those usually do not have 1gb. If the device has 32 bit counters only and it has a 1Gb Interface, then you would have to increase the polling rate to before the counter overlaps.

Here are the OIDs for both 32 and 64 for reference.

32-bit Counter-based

OID = ifInOctets            1.3.6.1.2.1.2.2.1.10.

OID = ifInUcastPkts        1.3.6.1.2.1.2.2.1.11.

OID = ifInNUcastPkts      1.3.6.1.2.1.2.2.1.12.

OID = ifOutOctets          1.3.6.1.2.1.2.2.1.16.

OID = ifOutUcastPkts      1.3.6.1.2.1.2.2.1.17.

OID = ifOutNUcastPkts    1.3.6.1.2.1.2.2.1.18.

64-bit Counter-based

OID = ifHCInOctets             1.3.6.1.2.1.31.1.1.1.6.

OID = ifHCInUcastPkts        1.3.6.1.2.1.31.1.1.1.7.

OID = ifHCInMulticastPkts    1.3.6.1.2.1.31.1.1.1.8.

OID = ifHCOutOctets          1.3.6.1.2.1.31.1.1.1.10.

OID = ifHCOutUcastPkts      1.3.6.1.2.1.31.1.1.1.11.

OID = ifHCOutMulticastPkts 1.3.6.1.2.1.31.1.1.1.12.