Aggregator Error - Got unexpected error for detect change only write for attr

Products

• Network Observability
• CA Performance Management

Issue/Introduction

The following repeating error appears in the DA log:

ERROR | AbstractReconciler | ion.impl.AttirbuteChangeDetector | Got unexpected error for detect change only write for attr {http://##.##.##/inventory}Device.IPAddresses on item [ITEM_ID]: NULL_INPUT

Environment

DX NetOps Performance Management 25.4.5

Cause

This error occurs during the reconciliation process when the Data Aggregator encounters a malformed IP-MIB table (1.3.6.1.2.1.4.20) on a monitored device.

Standard SNMP implementation requires that the IP addresses themselves serve as the table instances (indexes). The error is triggered by two specific environmental issues:

1. Incorrect Indexing: The device uses integers (e.g., .1, .2, .3) as table instances instead of the IP addresses.
2. Duplicate IP Addresses: Because the IP addresses are supposed to be the unique instances, the presence of duplicate IPs within the table (reporting the same IP for multiple integer indexes) causes a NULL_INPUT failure during the change detection write.

Resolution

This is an environmental issue caused by the device's SNMP implementation. To resolve the error, contact the device vendor with a sapwalk or SNMP walk of the IP-MIB table and request the following:

1. Ensure that the table instances (OIDs) for the ipAddrTable (1.3.6.1.2.1.4.20) correctly use the IP addresses as the instance suffix.
2. Ensure that each IP address reported in the table is unique for that device entity.