The dig (Domain Information Groper) command is a network administration command-line tool for querying Domain Name System (DNS) servers. It is commonly used to troubleshoot DNS problems and to perform DNS lookups.

Here’s a cheat sheet for the dig command along with some common usages and example outputs:

Basic Syntax

dig [@server] [name] [type] [options]
  • @server: The DNS server to query (optional).
  • name: The domain name to query.
  • type: The type of DNS record to query (e.g., A, MX, NS, etc.).
  • options: Additional options to modify the command’s behavior.

Common Usages

  1. Basic A Record Lookup

    dig example.com

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12345
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            3600    IN      A       93.184.216.34

;; Query time: 20 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:34:56 UTC 2021
;; MSG SIZE  rcvd: 56

  2. Query a Specific DNS Server

    dig @8.8.8.8 example.com

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> @8.8.8.8 example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54321
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            3600    IN      A       93.184.216.34

;; Query time: 30 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:35:56 UTC 2021
;; MSG SIZE  rcvd: 56

  3. Query for MX Records

    dig example.com MX

    Example Output:

     ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com MX
 ;; global options: +cmd
 ;; Got answer:
 ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 67890
 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 3

 ;; QUESTION SECTION:
 ;example.com.                   IN      MX

 ;; ANSWER SECTION:
 example.com.            3600    IN      MX      10 mail.example.com.
 example.com.            3600    IN      MX      20 mail2.example.com.

 ;; Query time: 40 msec
 ;; SERVER: 8.8.8.8#53(8.8.8.8)
 ;; WHEN: Mon Oct 11 12:36:56 UTC 2021
 ;; MSG SIZE  rcvd: 100

  4. Query for NS Records

    dig example.com NS

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com NS
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13579
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      NS

;; ANSWER SECTION:
example.com.            3600    IN      NS      ns1.example.com.
example.com.            3600    IN      NS      ns2.example.com.

;; Query time: 50 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:37:56 UTC 2021
;; MSG SIZE  rcvd: 80

  5. Query for TXT Records

    dig example.com TXT

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24680
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      TXT

;; ANSWER SECTION:
example.com.            3600    IN      TXT     "v=spf1 include:_spf.example.com ~all"

;; Query time: 60 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:38:56 UTC 2021
;; MSG SIZE  rcvd: 80

  6. Query for CNAME Records

    dig www.example.com CNAME

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> www.example.com CNAME
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11223
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;www.example.com.               IN      CNAME

;; ANSWER SECTION:
www.example.com.        3600    IN      CNAME   example.com.

;; Query time: 70 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:39:56 UTC 2021
;; MSG SIZE  rcvd: 80

Additional Options

  • +short: Provides a concise output.

    dig example.com +short

    Example Output:

    93.184.216.34

  • +trace: Traces the path to the authoritative DNS server.

    dig example.com +trace

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com +trace
;; global options: +cmd
.                       518400  IN      NS      a.root-servers.net.
.                       518400  IN      NS      b.root-servers.net.
...
example.com.            172800  IN      NS      ns1.example.com.
example.com.            172800  IN      NS      ns2.example.com.
ns1.example.com.        172800  IN      A       192.0.2.1
example.com.            3600    IN      A       93.184.216.34

  • +noall +answer: Shows only the answer section.

    dig example.com +noall +answer

    Example Output:

    example.com.            3600    IN      A       93.184.216.34

Validating and Tracing an A record

Using the dig command to validate an A record and trace it out:

Validating an A Record

To validate an A record, you can use the dig command to query the DNS server for the A record of a specific domain.

Basic A Record Lookup

dig example.com A

Example Output:

; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com A
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12345
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            3600    IN      A       93.184.216.34

;; Query time: 20 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:34:56 UTC 2021
;; MSG SIZE  rcvd: 56

Concise Output

To get a concise output showing only the IP address:

dig example.com A +short

Example Output:

93.184.216.34

Tracing the A Record

To trace the path to the authoritative DNS server for an A record, you can use the +trace option.

Trace the DNS Path

dig example.com +trace

Example Output:

; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> example.com +trace
;; global options: +cmd
.                       518400  IN      NS      a.root-servers.net.
.                       518400  IN      NS      b.root-servers.net.
...
example.com.            172800  IN      NS      ns1.example.com.
example.com.            172800  IN      NS      ns2.example.com.
ns1.example.com.        172800  IN      A       192.0.2.1
example.com.            3600    IN      A       93.184.216.34

Additional Useful Options

  • +noall +answer: Shows only the answer section.

    dig example.com A +noall +answer

    Example Output:

    example.com.            3600    IN      A       93.184.216.34

  • @server: Query a specific DNS server.

    dig @8.8.8.8 example.com A

    Example Output:

    ; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> @8.8.8.8 example.com A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54321
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            3600    IN      A       93.184.216.34

;; Query time: 30 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 11 12:35:56 UTC 2021
;; MSG SIZE  rcvd: 56

Summary

  • Validate A Record:

    dig example.com A
dig example.com A +short

  • Trace A Record:

    dig example.com +trace

  • Additional Options:

    dig example.com A +noall +answer
dig @8.8.8.8 example.com A