CompTIA Server+ (SK0-005)TroubleshootingEasy
A server administrator is investigating a critical application on a Windows Server that is intermittently failing to connect to its SQL database. The application logs show 'Login timeout expired' errors. All other network services on the server appear to be functioning correctly, and the database server is accessible from other machines on the network. What is the MOST likely cause of this issue?
- AInsufficient RAM on the Windows Server causing application slowdowns.
- BThe SQL Server service on the database server is stopped.
- CA firewall on the Windows Server is blocking outbound connections to the SQL port.
- DIncorrect database credentials configured in the application.
Show answer & explanationAnswer & explanation
Correct answer: C. A firewall on the Windows Server is blocking outbound connections to the SQL port.
The 'Login timeout expired' error, combined with the database being accessible from other machines, strongly suggests a network connectivity issue originating from the application server itself. A local firewall blocking outbound connections is a common cause for such specific application-level connection failures.
Why the other options are wrong
- A. Insufficient RAM would cause general system slowdowns or application crashes, not typically a specific 'login timeout expired' error for a remote resource if network connectivity is otherwise fine.
- B. If the SQL Server service was stopped, no other machines would be able to connect to it, contradicting the scenario.
- D. Incorrect credentials would likely result in an 'authentication failed' error, not a 'timeout expired'.
Application Firewall Blocking
A local firewall on a server can block specific outbound or inbound connections for applications, leading to connection timeouts or failures.
- Often configured per-application or per-port.
- Can be Windows Firewall, iptables, or third-party software.
- Troubleshoot by checking firewall logs or temporarily disabling for testing.
Memory trick: When an app can't connect, check the path, especially the gatekeeper.