Abstract: An information handling system, such as a disc drive, includes a controller that communicates with other devices in a loop, and performs distributed or peer-to-peer loop error diagnostics. One example of a loop is a fiber channel arbitrated loop. Distributed or peer-to-peer loop error diagnostics identifies and diagnoses errors in the immediately upstream device and the immediately upstream link by monitoring the error count to determine of the error count is increasing or not. An increasing error count or a changed loop configuration indicates that the source of the error is not the upstream device, while an unchanging error count and an unchanged loop configuration indicates that the source of the error is the upstream link.