Linux "dig" Command Line Options and Examples
DNS lookup utility

dig is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name server(s) that were queried. Most DNS administrators use dig to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output.


dig [@server] [-b address] [-c class] [-f filename] [-k filename] [-m] [-p port#] [-q name] [-t type] [-v] [-x addr]
[-y [hmac:]name:key] [[-4] | [-6]] [name] [type] [class] [queryopt...]

Command Line Options:

Set the source IP address of the query. The address must be a valid address on one of the host's network interfaces, or ""or "::". An optional port may be specified by appending "#<port>"
dig -b ...
Set the query class. The default class is IN; other classes are HS for Hesiod records or CH for Chaosnet records.
dig -c ...
Batch mode: dig reads a list of lookup requests to process from the given file. Each line in the file should be organized in thesame way they would be presented as queries to dig using the command-line interface.
dig -f ...
Do reverse IPv6 lookups using the obsolete RFC1886 IP6.INT domain, which is no longer in use. Obsolete bit string label queries(RFC2874) are not attempted.
dig -i ...
Sign queries using TSIG using a key read from the given file. Key files can be generated using tsig-keygen(8). When using TSIGauthentication with dig, the name server that is queried needs to know the key and algorithm that is being used. In BIND, this isdone by providing appropriate key and server statements in named.conf.
dig -k ...
Enable memory usage debugging.
dig -m ...
Send the query to a non-standard port on the server, instead of the default port 53. This option would be used to test a nameserver that has been configured to listen for queries on a non-standard port number.
dig -p ...
The domain name to query. This is useful to distinguish the name from other arguments.
dig -q ...
The resource record type to query. It can be any valid query type which is supported in BIND 9. The default query type is "A",unless the -x option is supplied to indicate a reverse lookup. A zone transfer can be requested by specifying a type of AXFR.When an incremental zone transfer (IXFR) is required, set the type to ixfr=N. The incremental zone transfer will contain thechanges made to the zone since the serial number in the zone's SOA record was N.
dig -t ...
Print query times in microseconds instead of milliseconds.
dig -u ...
Print the version number and exit.
dig -v ...
Simplified reverse lookups, for mapping addresses to names. The addr is an IPv4 address in dotted-decimal notation, or acolon-delimited IPv6 address. When the -x is used, there is no need to provide the name, class and type arguments. digautomatically performs a lookup for a name like and sets the query type and class to PTR and INrespectively. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain (but see also the -i option).
dig -x ...
Sign queries using TSIG with the given authentication key. keyname is the name of the key, and secret is the base64 encodedshared secret. hmac is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256,hmac-sha384, or hmac-sha512. If hmac is not specified, the default is hmac-md5 or if MD5 was disabled hmac-sha256.NOTE: You should use the -k option and avoid the -y option, because with -y the shared secret is supplied as a command lineargument in clear text. This may be visible in the output from ps(1) or in a history file maintained by the user's shell.QUERY OPTIONSdig provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set orreset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout andretry strategies.Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be precededby the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They havethe form +keyword=value. Keywords may be abbreviated, provided the abbreviation is unambiguous; for example, +cd is equivalent to+cdflag. The query options are:+[no]aaflagA synonym for +[no]aaonly.+[no]aaonlySets the "aa" flag in the query.+[no]additionalDisplay [do not display] the additional section of a reply. The default is to display it.+[no]adflagSet [do not set] the AD (authentic data) bit in the query. This requests the server to return whether all of the answer andauthority sections have all been validated as secure according to the security policy of the server. AD=1 indicates that allrecords have been validated as secure and the answer is not from a OPT-OUT range. AD=0 indicate that some part of the answer wasinsecure or not validated. This bit is set by default.+[no]allSet or clear all display flags.+[no]answerDisplay [do not display] the answer section of a reply. The default is to display it.+[no]authorityDisplay [do not display] the authority section of a reply. The default is to display it.+[no]badcookieRetry lookup with the new server cookie if a BADCOOKIE response is received.+[no]besteffortAttempt to display the contents of messages which are malformed. The default is to not display malformed answers.+bufsize=BSet the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0respectively. Values outside this range are rounded up or down appropriately. Values other than zero will cause a EDNS query tobe sent.+[no]cdflagSet [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation ofresponses.+[no]classDisplay [do not display] the CLASS when printing the record.+[no]cmdToggles the printing of the initial comment in the output identifying the version of dig and the query options that have beenapplied. This comment is printed by default.+[no]commentsToggle the display of comment lines in the output. The default is to print comments.+[no]cookie[=####]Send a COOKIE EDNS option, with optional value. Replaying a COOKIE from a previous response will allow the server to identify aprevious client. The default is +cookie.+cookie is also set when +trace is set to better emulate the default queries from a nameserver.+[no]cryptoToggle the display of cryptographic fields in DNSSEC records. The contents of these field are unnecessary to debug most DNSSECvalidation failures and removing them makes it easier to see the common failures. The default is to display the fields. Whenomitted they are replaced by the string "[omitted]" or in the DNSKEY case the key id is displayed as the replacement, e.g. "[ keyid = value ]".+[no]defnameDeprecated, treated as a synonym for +[no]search+[no]dnssecRequests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query.+domain=somenameSet the search list to contain the single domain somename, as if specified in a domain directive in /etc/resolv.conf, and enablesearch list processing as if the +search option were given.+dscp=valueSet the DSCP code point to be used when sending the query. Valid DSCP code points are in the range [0..63]. By default no codepoint is explicitly set.+[no]edns[=#]Specify the EDNS version to query with. Valid values are 0 to 255. Setting the EDNS version will cause a EDNS query to be sent.+noedns clears the remembered EDNS version. EDNS is set to 0 by default.+[no]ednsflags[=#]Set the must-be-zero EDNS flags bits (Z bits) to the specified value. Decimal, hex and octal encodings are accepted. Setting anamed flag (e.g. DO) will silently be ignored. By default, no Z bits are set.+[no]ednsnegotiationEnable / disable EDNS version negotiation. By default EDNS version negotiation is enabled.+[no]ednsopt[=code[:value]]Specify EDNS option with code point code and optionally payload of value as a hexadecimal string. code can be either an EDNSoption name (for example, NSID or ECS), or an arbitrary numeric value. +noednsopt clears the EDNS options to be sent.+[no]expireSend an EDNS Expire option.+[no]failDo not try the next server if you receive a SERVFAIL. The default is to not try the next server which is the reverse of normalstub resolver behavior.+[no]header-onlySend a query with a DNS header without a question section. The default is to add a question section. The query type and queryname are ignored when this is set.+[no]identifyShow [or do not show] the IP address and port number that supplied the answer when the +short option is enabled. If short formanswers are requested, the default is not to show the source address and port number of the server that provided the answer.+[no]idnoutConvert [do not convert] puny code on output. This requires IDN SUPPORT to have been enabled at compile time. The default is toconvert output.+[no]ignoreIgnore truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed.+[no]keepopenKeep the TCP socket open between queries and reuse it rather than creating a new TCP socket for each lookup. The default is+nokeepopen.+[no]mappedAllow mapped IPv4 over IPv6 addresses to be used. The default is +mapped.+[no]multilinePrint records like the SOA records in a verbose multi-line format with human-readable comments. The default is to print eachrecord on a single line, to facilitate machine parsing of the dig output.+ndots=DSet the number of dots that have to appear in name to D for it to be considered absolute. The default value is that defined usingthe ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relativenames and will be searched for in the domains listed in the search or domain directive in /etc/resolv.conf if +search is set.+[no]nsidInclude an EDNS name server ID request when sending a query.+[no]nssearchWhen this option is set, dig attempts to find the authoritative name servers for the zone containing the name being looked up anddisplay the SOA record that each name server has for the zone.+[no]onesoaPrint only one (starting) SOA record when performing an AXFR. The default is to print both the starting and ending SOA records.+[no]opcode=valueSet [restore] the DNS message opcode to the specified value. The default value is QUERY (0).+[no]qrPrint [do not print] the query as it is sent. By default, the query is not printed.+[no]questionPrint [do not print] the question section of a query when an answer is returned. The default is to print the question section asa comment.+[no]rdflagA synonym for +[no]recurse.+[no]recurseToggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means dig normally sendsrecursive queries. Recursion is automatically disabled when the +nssearch or +trace query options are used.+retry=TSets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include theinitial query.+[no]rrcommentsToggle the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). Thedefault is not to print record comments unless multiline mode is active.+[no]searchUse [do not use] the search list defined by the searchlist or domain directive in resolv.conf (if any). The search list is notused by default.'ndots' from resolv.conf (default 1) which may be overridden by +ndots determines if the name will be treated as relative or notand hence whether a search is eventually performed or not.+[no]shortProvide a terse answer. The default is to print the answer in a verbose form.+[no]showsearchPerform [do not perform] a search showing intermediate results.+[no]sigchaseChase DNSSEC signature chains. Requires dig be compiled with -DDIG_SIGCHASE. This feature is deprecated. Use delv instead.+split=WSplit long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearestmultiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters whenmultiline mode is active.+[no]statsThis query option toggles the printing of statistics: when the query was made, the size of the reply and so on. The defaultbehavior is to print the query statistics.+[no]subnet=addr[/prefix-length]Send (don't send) an EDNS Client Subnet option with the specified IP address or network prefix.dig +subnet=, or simply dig +subnet=0 for short, sends an EDNS CLIENT-SUBNET option with an empty address and a sourceprefix-length of zero, which signals a resolver that the client's address information must not be used when resolving this query.+[no]tcpUse [do not use] TCP when querying name servers. The default behavior is to use UDP unless a type any or ixfr=N query isrequested, in which case the default is TCP. AXFR queries always use TCP.+timeout=TSets the timeout for a query to T seconds. The default timeout is 5 seconds. An attempt to set T to less than 1 will result in aquery timeout of 1 second being applied.+[no]topdownWhen chasing DNSSEC signature chains perform a top-down validation. Requires dig be compiled with -DDIG_SIGCHASE. This feature isdeprecated. Use delv instead.+[no]traceToggle tracing of the delegation path from the root name servers for the name being looked up. Tracing is disabled by default.When tracing is enabled, dig makes iterative queries to resolve the name being looked up. It will follow referrals from the rootservers, showing the answer from each server that was used to resolve the lookup.If @server is also specified, it affects only the initial query for the root zone name servers.+dnssec is also set when +trace is set to better emulate the default queries from a nameserver.+tries=TSets the number of times to try UDP queries to server to T instead of the default, 3. If T is less than or equal to zero, thenumber of tries is silently rounded up to 1.+trusted-key=####Specifies a file containing trusted keys to be used with +sigchase. Each DNSKEY record must be on its own line.If not specified, dig will look for /etc/trusted-key.key then trusted-key.key in the current directory.Requires dig be compiled with -DDIG_SIGCHASE. This feature is deprecated. Use delv instead.+[no]ttlidDisplay [do not display] the TTL when printing the record.+[no]ttlunitsDisplay [do not display] the TTL in friendly human-readable time units of "s", "m", "h", "d", and "w", representing seconds,minutes, hours, days and weeks. Implies +ttlid.+[no]unknownformatPrint all RDATA in unknown RR type presentation format (RFC 3597). The default is to print RDATA for known types in the type'spresentation format.+[no]vcUse [do not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards compatibility. The"vc" stands for "virtual circuit".+[no]zflagSet [do not set] the last unassigned DNS header flag in a DNS query. This flag is off by default.MULTIPLE QUERIESThe BIND 9 implementation of dig supports specifying multiple queries on the command line (in addition to supporting the -f batchfile option). Each of those queries can be supplied with its own set of flags, options and query options.In this case, each query argument represent an individual query in the command-line syntax described above. Each consists of any ofthe standard options and flags, the name to be looked up, an optional query type and class and any query options that should beapplied to that query.A global set of query options, which should be applied to all queries, can also be supplied. These global query options must precedethe first tuple of name, class, type, options, flags, and query options supplied on the command line. Any global query options(except the +[no]cmd option) can be overridden by a query-specific set of query options. For example:dig +qr any -x ns +noqrshows how dig could be used from the command line to make three lookups: an ANY query for, a reverse lookup of a query for the NS records of A global query option of +qr is applied, so that dig shows the initial query it made foreach lookup. The final query has a local query option of +noqr which means that dig will not print the initial query when it looks upthe NS records for SUPPORTIf dig has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. digappropriately converts character encoding of domain name before sending a request to DNS server or displaying a reply from theserver. If you'd like to turn off the IDN support for some reason, defines the IDN_DISABLE environment variable. The IDN support isdisabled if the variable is set when dig runs.FILES/etc/resolv.conf${HOME}/.digrc
dig -y ...