# Inspect, clean, and verify.

Editorial revision 2026-11-01 — engineering guidance, not a released model specification.

Use observations to guide work on the optical connection.

## Make inspection safe

Follow the equipment's laser-safety procedure and disable the relevant optical sources before disconnecting or inspecting. Never look directly into a fiber or connect an inspection scope to a live source.

## Inspect before cleaning

Use the correct inspection adapter for the connector. When contamination is present, use an approved procedure and tool for that interface, then inspect again. Do not treat lensed receptacles as exposed ferrules or improvise a wet-cleaning procedure.

## Record the result

A clean-looking connector does not establish the entire link's health. Record the observed condition and the subsequent link behavior. For errors or flaps, retain time-correlated alarms and per-lane measurements where available, then compare against the applicable model and host limits.

In practice / Worked example

## Record the result, not just “cleaned.”

For a contaminated connection, preserve evidence before and after intervention. Make the path safe using the equipment procedure before inspection; do not inspect a live optical source.

| Stage | Record |
| Before | Connector, inspection adapter, image and affected position |
| Action | Approved cleaning method and tool |
| Reinspection | New image, acceptance profile and result |
| Reconnection | Both mating interfaces checked; time recorded |
Cleaning is an action; satisfactory reinspection is a separate result. If contamination persists, retain the failed result and follow the manufacturer’s procedure. Lensed receptacles need their own instructions rather than exposed-ferrule treatment. End-face inspection also does not replace loss or operational testing.

Source: Cisco · Inspection and Cleaning Procedures for Fiber-Optic Connections ↗ Document 51834 · 30 November 2016 · editorial record format; equipment-specific instructions govern

## Before you specify

- Optical sources made safe

- Appropriate inspection and cleaning procedure

- Recorded condition and subsequent link behavior

## Sources & scope

General engineering guidance. External examples describe their own products and do not establish WBN availability or qualification.

- Inspection and cleaning procedures ↗ Cisco · Document 51834 · online reference

- Troubleshoot fiber links on Catalyst 9000 ↗ Cisco · Document 222738 · platform-specific examples

Source: Cisco · Inspection and Cleaning Procedures for Fiber-Optic Connections ↗ — https://www.cisco.com/c/en/us/support/docs/optical/synchronous-digital-hierarchy-sdh/51834-cleanfiber2.html
Source: Inspection and cleaning procedures ↗ — https://www.cisco.com/c/en/us/support/docs/optical/synchronous-digital-hierarchy-sdh/51834-cleanfiber2.html
Source: Troubleshoot fiber links on Catalyst 9000 ↗ — https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9200-switch-stack/222738-troubleshoot-fiber-links-on-catalyst-900.html