Symptoms

Discovery on IP switch fails with below error:

Error: 
CMDB Identification Error: Found invalid sys_id in payload. No record with sys_id [sys_id value] exist in table [cmdb_ci_ip_switch] or is a duplicate record with [discovery_source]...

Release

Any

Cause

There are duplicate records available for the same serial number in the CI table as well as Serial Number table 

You can search the CI record with a sys_id value in error and verify that discovery_source value of this record is "Duplicate"

Also navigate to the Serial Number table and verify that there are duplicate records for the same serial number but pointing to a different CI's where one the CI record is duplicate

Resolution

Remove the duplicate records.