Direct answer
A failure immediately after a known change should be checked for new defaults, stale pairing, power sequencing or compatibility before factory recovery. For carrier-grade NAT and public inbound access, first compare router WAN address with an external address and test the service locally.
What this covers
- carrier-grade NAT and public inbound access with this exact failure state
- Diagnosis across router forwarding versus provider CGNAT, IPv6 and service listening state
- Customer-accessible observation, settings and external components
What it does not cover
- ×A displayed manufacturer error code with a different documented meaning
- ×Live electrical, sealed-system, internal battery-cell or gas repair
- ×A claim that every model exposes identical controls
Capture the exact failure state
ReversibleRecord the change, version, outage time or newly connected hardware and the last known working state. Expected behavior: provide outbound internet while recognizing when no unique public IPv4 is assigned.
Isolate the component boundary
ReversibleCompare router WAN address with an external address and test the service locally. Remove or roll back only the reversible change, or test the previous direct path. Boundary to separate: router forwarding versus provider CGNAT, IPv6 and service listening state.
Correct only the proven cause
ReversibleRequest a public address, use supported IPv6 or a secure relay/VPN design. Reapply compatible settings, update both endpoints or replace the incompatible new path.
Verify and stop safely
ReversibleRestart twice and confirm the feature remains stable with the intended change present. Do not expose remote desktop, cameras or admin panels without strong authentication.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Exact questions
Common follow-ups
What should I check first when carrier-grade NAT and public inbound access has this problem?+
Compare router WAN address with an external address and test the service locally.
Why not factory-reset immediately?+
The useful boundary is router forwarding versus provider CGNAT, IPv6 and service listening state. A reset can erase state without proving which side failed.
When should I stop troubleshooting?+
do not expose remote desktop, cameras or admin panels without strong authentication.
Answer for the exact device and software version shown above.