Separate names from connectivity

Network+: Network Troubleshooting
Original starter lesson / sources checked 2026-09-30

DNS maps names to records; it does not replace routing. A service can be reachable by address while a hostname fails.

Inspect the configured resolver, query the relevant record, and compare results with the expected destination. Cached or split DNS may produce different answers.

A successful name lookup does not prove the application port or TLS handshake works. Verify each boundary separately.

Hands-on lab

Query a test hostname and record the returned address and resolver.
Draw the sequence: name lookup, connection, TLS if used, application response.

Put the lesson to work

Original exam-style practice. Choose the best answer for the stated scenario.

1. A hostname resolves to the correct IP, but HTTPS connections time out. What does the lookup establish?

The entire application worksThe password is correctName resolution succeeded; connectivity still needs investigationAll firewall rules are correct

2. A device can reach an IP but fails to resolve its hostname. Which test is most targeted?

Inspect the application certificate chainQuery the configured DNS resolver for that hostnameMeasure the wireless signal strengthCheck the route to the already reachable IP

Go deeper

Official CompTIA scope and exam information WWADD Move: fetch JSON with error handling

Independent practice aligned to selected topics. No endorsement, actual exam items, or pass guarantee. Verify your exam version and use the full official objectives for complete preparation.