Dig (command)

dig (domain information groper) is a network administration command-line tool for querying Domain Name System (DNS) name servers.

Dig is useful for network troubleshooting and for educational purposes. Dig can operate in interactive command line mode or in batch mode by reading requests from an operating system file. When a specific name server is not specified in the command invocation, it will use the operating systems default resolver, usually configured via the resolv.conf file. Without any arguments it queries the DNS root zone.

Dig supports Internationalized Domain Name (IDN) queries.

Dig is part of the BIND domain name server software suite. Dig replaces older tools such as nslookup and the host program.

Example usage

In this example, dig is used to query for any type of record information in the domain example.com:

• Command line:

dig any example.com

• Output:

; <<>> DiG 9.6.1 <<>> any example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4016
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

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

;; ANSWER SECTION:
example.com.            172719  IN      NS      a.iana-servers.net.
example.com.            172719  IN      NS      b.iana-servers.net.
example.com.            172719  IN      A       208.77.188.166
example.com.            172719  IN      SOA     dns1.icann.org. hostmaster.icann.org. 2007051703 7200 3600 1209600 86400

;; Query time: 1 msec
;; SERVER: ::1#53(::1)
;; WHEN: Wed Aug 12 11:40:43 2009
;; MSG SIZE  rcvd: 154

Queries may be directed to designated DNS servers for specific records; in this example, MX records:

• Command:

dig MX wikimedia.org @ns0.wikimedia.org

• Output:

; <<>> DiG 9.6.1 <<>> MX wikimedia.org @ns0.wikimedia.org
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61144
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;wikimedia.org.                 IN      MX

;; ANSWER SECTION:
wikimedia.org.          3600    IN      MX      10 mchenry.wikimedia.org.
wikimedia.org.          3600    IN      MX      50 lists.wikimedia.org.

;; ADDITIONAL SECTION:
mchenry.wikimedia.org.  3600    IN      A       208.80.152.186
lists.wikimedia.org.    3600    IN      A       91.198.174.5

;; Query time: 73 msec
;; SERVER: 208.80.152.130#53(208.80.152.130)
;; WHEN: Wed Aug 12 11:51:03 2009
;; MSG SIZE  rcvd: 109

See also

• List of DNS record types
• nslookup, a similar tool
• whois
• host (Unix), a simple utility for performing Domain Name System lookups

References

Paul Albitz and Cricket Liu. DNS and BIND, 5th Edition. Nutshell Series. O'Reilly and Associates, Inc., 2006.

External links

• dig manual page as distributed with BIND 9.9
• dig – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group
• How to use dig to query DNS name servers