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SNMP ifInOctets and ifOutOctets not working after upgrade to AIX 7200-05-03

Question & Answer


Question

Why did SNMP ifInOctets and ifOutOctets MIBs stop working after an upgrade to AIX 7200-05-03?

Answer

Starting with AIX 7200-05-03, the ifstats32 network option is disabled by default.
This can be confirmed by the command below:
# no -a | grep ifstats32
                ifstats32 = 0
When ifstats32 is set to zero, it is disabled and applications that need to access ifstats32 statistics, such as SNMP will not be able to do so.
This is the reason that SNMP queries for ifInOctets and ifOutOctets return a zero value.
The ifstats32 option was introduced to solve a performance problem documented by APAR IJ33459.
https://www.ibm.com/support/pages/apar/IJ33459
Once ifstats32 is disabled, there is no way for the current SNMP implementation to access ifstats32 data.
To enable ifstats32 again, run this command:
# no -p -o ifstats32=1
ifstats32 has been replaced with ifstats64, which doesn't have the performance issue, but unfortunately SNMP doesn't support ifstats64 at this time.
So based on this, if SNMP ifstats32 are required, then ifstats32 must be enabled and there is a risk of a performance impact if the environment matches the APAR IJ33459 description.
If monitoring ifstats32 is not a requirement, then leave ifstats32 disabled.

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Document Information

Modified date:
14 June 2022

UID

ibm16572441