Month: June 2009

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Dig command examples

The dig utility is very handy for troubleshooting name resolution issues or to find out information about an IP or a domain name. Here are some useful command examples.

Lookup for a domain

# dig google.com

; <<>> DiG 9.3.4-P1.2 <<>> google.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24311
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

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

;; ANSWER SECTION:
google.com. 217 IN A 216.58.209.238

;; Query time: 0 msec
;; SERVER: 62.210.64.50#53(62.210.64.50)
;; WHEN: Tue Oct 25 11:10:01 2016
;; MSG SIZE rcvd: 44

Lookup for a specific record

You can specify record type using the appropriate prefix:

# dig <prefix> google.com
  • A for A records
  • MX for MX records
  • NS for NameServer records
  • CNAME for cname records
  • TXT for SPF, DKIM and everything that goes inside TXT records

Short answer

If you want just the answer without any comments, you can use the +short option:

# dig A google.com +short
216.58.209.238

You can also enable or disable each output sections, using the appropriate paramaters. For example to get only the ANSWER SECTION:

# dig A google.com +noall +answer
google.com.             299     IN      A       74.125.140.139
google.com.             299     IN      A       74.125.140.101
google.com.             299     IN      A       74.125.140.100
google.com.             299     IN      A       74.125.140.138
google.com.             299     IN      A       74.125.140.113
google.com.             299     IN      A       74.125.140.102

Use a Specific DNS server

To test the answer from a specific DNS server you can use the @ parameter:

# dig A @8.8.8.8 google.com

; <<>> DiG 9.3.4-P1.2 <<>> A @8.8.8.8 google.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28263
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0

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

;; ANSWER SECTION:
google.com. 299 IN A 74.125.140.100
google.com. 299 IN A 74.125.140.113
google.com. 299 IN A 74.125.140.138
google.com. 299 IN A 74.125.140.139
google.com. 299 IN A 74.125.140.102
google.com. 299 IN A 74.125.140.101

;; Query time: 8 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Oct 25 11:15:23 2016
;; MSG SIZE rcvd: 124

Reverse lookup

You can check the PTR records by doing a reverse lookup:

# dig -x 91.189.94.40

; <<>> DiG 9.3.4-P1.2 <<>> -x 91.189.94.40
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21503
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 0

;; QUESTION SECTION:
;40.94.189.91.in-addr.arpa. IN PTR

;; ANSWER SECTION:
40.94.189.91.in-addr.arpa. 3600 IN PTR ovinnik.canonical.com.

;; AUTHORITY SECTION:
94.189.91.in-addr.arpa. 3600 IN NS ns1.canonical.com.
94.189.91.in-addr.arpa. 3600 IN NS ns2.canonical.com.
94.189.91.in-addr.arpa. 3600 IN NS ns3.canonical.com.

;; Query time: 15 msec
;; SERVER: 62.210.64.50#53(62.210.64.50)
;; WHEN: Tue Oct 25 11:43:36 2016
;; MSG SIZE rcvd: 132