Interface showing over 100% bandwidth out

book

Article ID: 207081

calendar_today

Updated On:

Products

CA Infrastructure Management

Issue/Introduction

We have an interface that is showing over 100% utilization. Speed is set correct. How can the link go over 100% 

How to verify bandwidth utilization on an interface 

How to verify bandwidth utilization on a link

What is the calculation for bandwidth utilization 

Link showing over 100% Bandwidth utilization 

Environment

Release : 20.2

Component : IM Reporting / Admin / Configuration

Resolution

Find a time when the utilization out went over 100% in the debug. 
Find the CalculatedSpeed of the interface/link
Check the prior poll and current poll to get the value of bytes that were processed over the 5 minute (300 second) interval between polls. Make sure it matches the delta value in the debug. 
Run the raw values through the standard bandwidth calculation. (Octets*8*100)/(seconds*ifSpeed) and make sure they match the Poll Response after data processing

Example verifying a out link showing over 100% 

CalculatedSpeedOut: 50000000 (Long)

poll at 10:13 of 1.3.6.1.2.1.31.1.1.1.10 ifHCOutOctets value=48202627556349
Debug log entry:
Jan 19 20:13:49.496: SnmpResponseVariable [oid=1.3.6.1.2.1.31.1.1.1.10.8251, type=COUNTER64, value=48202627556349, isDelta=true, isList=true, error=SUCCESS, isDynamicIndex=false, indexList=null]

poll at 20:18 of 1.3.6.1.2.1.31.1.1.1.10 ifHCOutOctets value=48202627556349
Debug log entry:
Jan 19 20:18:49.496: SnmpResponseVariable [oid=1.3.6.1.2.1.31.1.1.1.10.8251, type=COUNTER64, value=48202627556349, isDelta=true, isList=true, error=SUCCESS, isDynamicIndex=false, indexList=null]

Difference between polls (DELTA) 48202627556349-48200552131606 = 2075424743 octets
Debug log entry:
Jan 19 20:18:49.497: SnmpResponseVariable [oid=1.3.6.1.2.1.31.1.1.1.10.8251, type=COUNTER64, value=2075424743, isDelta=true, isList=true, error=SUCCESS, isDynamicIndex=false, indexList=null]

Then we calculate bandwidth using the standard formula resulting in out bandwidth of 110.6893196266667.
(IfOutOctets*8*100) / (seconds*ifSpeed)

(2075424743*8*100) / (300*50000000)
1660339794400/15000000000 = 110.6893196266667

The same value manually calculated is what we put into CAPM database. 
Debug log entry:
Jan 19 20:18:49.497: DCMResponseVariable [name={http://im.ca.com/normalizer}NormalizedPortInfo.UtilizationOut, value=110.68931962666666 (Double) ]