A syslog server is configured to use UDP port 514. The administrator uses Telnet to check port 514 against the syslog server. However, the syslog server is not responding. Which of the following is…

A downed syslog server does not explain the test failure, because Telnet cannot test UDP ports at all - the result would be the same even if the server were running.

Telnet operates exclusively over TCP and relies on TCP's three-way handshake to establish a connection. Since syslog uses UDP port 514, which is connectionless and does not support TCP handshakes, Telnet will always fail to connect regardless of whether the syslog service is actually running and healthy.

While a firewall blocking UDP 514 is possible, the more fundamental and likely reason for failure is that Telnet uses TCP and is inherently incapable of testing UDP ports.

A full log might cause syslog to stop writing entries but would not cause the server to stop listening on the network port, and it does not explain why the Telnet test fails.