The CMDB Identification Engine displays the following error when it encounters two network adapters with same IP and MAC address:

Error CMDB Identification Error: Found duplicate Lookup items (6 and 7) in the payload index 0 using fields ip_address,mac_address

This occurs because the identification rule cannot uniquely identify a network adapter record. 

1. Using a Kingston instance, discover a Linux server that has multiple “bonded” adapters.

   Because these adapters represent a single, logical link, each adapter has the same IP address and MAC address.

2. Observe the Discovery results.

   Discovery for Kingston does not return secondary adapters and, therefore, cannot detect duplicates. Discovery completes successfully and finds only one adapter.

3. Using a London instance (either new or upgraded), discover the same server.

   Discovery for London discovers all the adapters on the host, including those adapters with the same IP and MAC addresses. Discovery fails and displays this error:

"CMDB Identification Error: Found duplicate Lookup items (8 and 18) in the payload index 0 using fields ip_address,mac_address">

The root cause of this PRB is that the Hardware identification rule is not able to uniquely identify a record in the Network Adapter [cmdb_ci_network_adapter] table. There are two possible workarounds:

• Ensure that either the IP or MAC address on each adapter is unique.
• Add "Name" to the Hardware Rule.

To add the "Name" parameter to the rule:

1. Navigate to Discovery Definition > CI Identification > Identifiers.

2. Select the Hardware Rule identifier.

3. Select the Identifier Entries related list.

4. Open the record for the Network Adapter [cmdb_ci_network_adapter] table.

5. Open the lock on the Criterion attributes field and add Name (from the cmdb_ci_network_adapter table) to the list of attributes.

6. Lock the field and update the record.

CAUTION: If you add the "Name" parameter to the Hardware Rule and then change the name of an adapter, Discovery cannot resolve an existing CI for that adapter. Discovery labels the Install Status of that CI as "Absent" and creates another CI.