# Reflection: Same Diagnosis, New Layer

## Reflection questions

1. How much of this module's Lab did you solve using pure Docker knowledge, versus reasoning
   you already had from ROOT 02?
2. Where do you expect "published port" reasoning to matter again later in ROOT 05+?

## Real Ops takeaway

**"Works internally, unreachable externally" is one of the single most common real-world
container networking incidents — and you just diagnosed and fixed a real one.** The exact
reasoning you used here (confirm internal health, check what's actually published, verify the
published mapping works) is the same reasoning you'll use again for Kubernetes Services later —
"published port" becomes "Service," but the underlying question (is anything actually routing
traffic to this workload?) doesn't change.

This module is complete. Continue to the next module.

## Instructor Notes

**Discussion questions for a live classroom:** question 2 previews Kubernetes Services directly
— worth naming that connection explicitly without teaching Services yet.

**Approximate timing:** 5-8 minutes live discussion; 5 minutes self-paced writing.