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Zorluk: OrtaTroubleshooting DNS and Name Resolution Services

A network administrator is troubleshooting name resolution issues on a Linux workstation. The administrator runs the command `dig @10.0.0.5 webserver.company.local` and receives the following output:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18402
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;webserver.company.local. IN A

Which of the following is the most accurate interpretation of this command output?

  1. The DNS server is reachable and active, but no IPv4 address (A) record exists for the requested hostname.Cevap
  2. B
    The DNS server does not exist or failed to respond on UDP port 53, resulting in a query timeout.
  3. C
    The domain name `webserver.company.local` is completely invalid and was rejected by the authoritative server with an NXDOMAIN response.
  4. D
    The DNS server requires clients to request IPv6 resolution using AAAA records before processing IPv4 address requests.

Cevap

The DNS server processed the request successfully (NOERROR), but no IPv4 address (A) record is configured for the requested hostname (ANSWER: 0).
The command output header status `NOERROR` confirms successful communication with the DNS server at 10.0.0.5, while `ANSWER: 0` shows that no host address (A) record is present for `webserver.company.local`.

Adım Adım Çözüm

1
Examine the status header of the output.
The header shows `status: NOERROR`, proving that communication with the DNS server succeeded and the query was processed without error.
Establishing whether the DNS server responded correctly is the first diagnostic step.
2
Analyze the ANSWER section count in the header.
The header indicates `ANSWER: 0`, meaning no resource records matching the query were returned.
Determining record presence isolates whether the issue is network reachability versus missing host configuration.
3
Synthesize the status code and answer count to determine the root cause.
The combination of NOERROR status and 0 answer records indicates the target host lacks an active A record on the DNS server.
Distinguishes between complete domain absence (NXDOMAIN), transport failures (timeouts), and missing specific records.

Anahtar Kavram

Interpreting DNS Query Status Codes and Answer Counts using CLI Tools
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