In the ldnsprobeOrder configuration, which probe is performed first?

In the ldnsprobeOrder configuration, which probe is performed first?

• A. DNS
• B. PING
• C. TCP
• D. UDP

Answer: (A)

The first probe is the DNS probe. In the ldnsprobeOrder configuration, the sequence of probes is defined for checking DNS-related health. Starting with the DNS probe validates that name resolution and DNS responses are functioning before testing other aspects of connectivity. If DNS resolution is unavailable or misbehaving, subsequent probes (PING, TCP, UDP) are less meaningful because the fundamental DNS path is already broken. The other probes test different transport-level aspects (ICMP reachability with PING, and port-level reachability with TCP and UDP), but they presume DNS resolution is working, which is why the DNS probe is performed first.

The first probe is the DNS probe. In the ldnsprobeOrder configuration, the sequence of probes is defined for checking DNS-related health. Starting with the DNS probe validates that name resolution and DNS responses are functioning before testing other aspects of connectivity. If DNS resolution is unavailable or misbehaving, subsequent probes (PING, TCP, UDP) are less meaningful because the fundamental DNS path is already broken. The other probes test different transport-level aspects (ICMP reachability with PING, and port-level reachability with TCP and UDP), but they presume DNS resolution is working, which is why the DNS probe is performed first.