A name lookup and a transport connection are different tests

A fictional office reports that a web application sometimes fails by hostname while a test to a documented server address succeeds. The application uses a certificate for its DNS name, and several clients cache answers from different recursive resolvers. A proposed firewall change would open every outbound port, but no capture or resolver comparison has yet been made. The approved exercise permits analysis of supplied logs and test results only; it does not authorize scanning outside systems or changing the production firewall. A later observation shows that the intended resolver returns an obsolete address for the name while the authoritative test record supplied by the administrator contains a newer address. The team must distinguish name resolution, TCP establishment, TLS identity validation and actual application behavior rather than treating one successful ping as a complete health check.