Method · 5 steps · Troubleshooting
Industrial network troubleshooting methodology.
When in doubt, follow the RIVER. Five steps from Layer 1 up: Reboot, Inspect, Verify, Examine, Replace. Physical first, because 80% of problems are physical.
Designed for the technician on shift, the apprentice in their first month, the experienced hand who needs a checklist to stay disciplined. Don't skip steps because you think you know the problem.
Originated by River Caudle
Step 01
Loose cable. Marginal connector. Stuck firmware after a power blip. The fastest fix in OT is often the one you'd never admit to in a postmortem.
"If it's not physically connected, it's not gonna work, homie."
Step 02
The vendor put lights on the device for a reason. Most failure modes show up here before any tool catches them. Solid green is a story; blinking amber is a story; dark is the loudest story of all.
"The lights don't lie — they're trying to tell you something."
Step 03
Half of OT outages are someone with the wrong VLAN tag or a /24 vs /16 mistake from three years ago. Verify against the documentation. If the documentation is wrong, fix the documentation.
"Match the documentation or make new documentation."
Step 04
By the time you're at Examine, you're spending real time. Make it count. The packets and the change log will tell you what physically present checks could not. Bring evidence to the meeting.
"Data doesn't lie. Opinions do."
Step 05
If the analysis says the device is bad and the line is bleeding money, swap. If the config is the problem, restore. The point is to get production back to green, then document so the next person doesn't pay the same tuition you did.
"When all else fails, nuke it from orbit."
§ The RIVER Rules™
Start at Layer 1 and work up. Don't skip steps because you think you know the problem. Half the time the device you were sure was bad turned out to have a loose patch cord.
If step 1 fixes it, you're done. Celebrate the easy wins. The fastest fix is the right fix — pride is not a troubleshooting strategy.
Screenshot everything for the next poor soul. Today's weird problem is tomorrow's known issue. The best troubleshooting happens when you're too lazy to do it twice.
§ Quick Reference
| Step | Action | Key question |
|---|---|---|
| R | Reboot & Reconnect | Is it physically connected and powered? |
| I | Inspect Indicators | What are the lights telling me? |
| V | Verify Vitals | Can I reach it? Is it configured correctly? |
| E | Examine Evidence | What do the logs and captures show? |
| R | Replace or Restore | Is it faster to fix or replace? |
"The best troubleshooting happens when you're too lazy to do it twice."
≈ The RIVER Method™ · River Caudle · MMXXVI