Custom SNMP OID Shows Data in SNMP Walk but Not in Lansweeper

[Obi_1_Cinobi]

Problem

When attempting to add custom OID data to assets in Lansweeper, the scan result returns “No data found.” However, performing an SNMP walk on the same device confirms that the OID returns valid values. This raises the question of why Lansweeper is unable to retrieve or display the data despite the OID being accessible via SNMP.

Difference Between SNMP Walk and SNMP Get

SNMP Get and SNMP Walk are both SNMP operations used to retrieve data from network devices, but they serve different purposes and behave differently.

SNMP Get

SNMP Get retrieves the value of one specific OID from a device.

SNMP Walk

SNMP Walk retrieves all OIDs under a given OID subtree by repeatedly performing SNMP Get-Next (or Get-Bulk) operations.

Why This Matters for Lansweeper

Lansweeper retrieves SNMP data using SNMP Get, not SNMP Walk. This means:

• The custom OID must be fully qualified, including any required index (for example .1, .0, etc.)
• An OID appearing in an SNMP Walk does not guarantee it can be retrieved with an SNMP Get unless the exact OID is known
• Table-based OIDs often require identifying the correct instance index before they can be queried successfully

This explains why an SNMP Walk may return values while Lansweeper reports “No data found.”

Troubleshooting

If custom SNMP OID scanning returns “No data found”, review the following Lansweeper Knowledge Base articles for detailed guidance and step-by-step instructions:

• How to set up custom OID scanning
  This article explains how to correctly configure custom SNMP OIDs in Lansweeper, including required fields, supported SNMP versions, and general configuration considerations.
  https://community.lansweeper.com/t5/scanning-your-network/scan-extra-snmp-data-with-custom-oid-scann...

• Troubleshooting custom OID scanning issues
  This article covers common causes of failed custom OID scans, such as incorrect OID formatting, missing index values, SNMP permission issues, and device-specific limitations. It also provides guidance on validating OIDs using SNMP tools and reviewing scan behavior.
  https://community.lansweeper.com/t5/troubleshooting-scanning-issues/troubleshooting-custom-oid-scann...

If the OID returns data during an SNMP walk but not during a Lansweeper scan, pay special attention to OID indexing and ensure the exact OID required for an SNMP Get is configured.

Recommendations

When validating custom SNMP OID data, Lansweeper recommends cross-referencing the results with a trusted SNMP testing tool, such as Paessler SNMP Tester or an equivalent utility.

When doing so, keep the following best practices in mind:

• Use SNMP Get, not SNMP Walk
  Lansweeper retrieves custom OID data using SNMP Get requests. Ensure your validation test also uses an SNMP Get operation against the exact OID, including any required index. An OID returning data in an SNMP walk does not guarantee it can be queried successfully via SNMP Get.

• Test from the Lansweeper scanning server
  Run the SNMP test from the same server that performs Lansweeper scanning. This ensures that network routing, firewalls, and access control behave identically to a Lansweeper scan.

• Use identical SNMP credentials
  Verify that the SNMP version, community string (for SNMPv1/v2c), or authentication and privacy settings (for SNMPv3) match exactly what is configured in Lansweeper.

• Confirm the exact OID format
  Ensure the OID tested in the SNMP tool matches the OID configured in Lansweeper, including any trailing .0 or table index values.

Following these recommendations helps eliminate environmental and configuration differences and ensures that SNMP test results accurately reflect what Lansweeper can retrieve during scanning.