Manual Pages for UNIX Darwin command on man dig

DIG(1) BIND9 DIG(1)

NAME

dig - DNS lookup utility

SYNOPSIS

ddiigg [@server] [-bb address] [-cc class] [-ff filename] [-kk filename] [-mm]

[-pp port#] [-tt type] [-xx addr] [-yy name:key] [-44] [-66] [name]

[type] [class] [queryopt...]

ddiigg [-hh]

ddiigg [global-queryopt...] [query...]

DESCRIPTION

ddiigg (domain information groper) 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 ddiigg to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output. Other lookup tools tend to have less functionality than ddiigg.

Although ddiigg is normally used with command-line arguments, it also has

a batch mode of operation for reading lookup requests from a file. A

brief summary of its command-line arguments and options is printed when

the -hh option is given. Unlike earlier versions, the BIND 9

implementation of ddiigg allows multiple lookups to be issued from the command line. Unless it is told to query a specific name server, ddiigg will try each of the servers listed in /etc/resolv.conf. When no command line arguments or options are given, ddiigg will perform an NS query for "." (the root).

It is possible to set per-user defaults for ddiigg via ${HOME}/.digrc.

This file is read and any options in it are applied before the command line arguments. The IN and CH class names overlap with the IN and CH top level domains

names. Either use the -tt and -cc options to specify the type and class,

or use "IN." and "CH." when looking up these top level domains. SSIIMMPPLLEE UUSSAAGGEE A typical invocation of ddiigg looks like:

dig @server name type

where: sseerrvveerr is the name or IP address of the name server to query. This can be

an IPv4 address in dotted-decimal notation or an IPv6 address in

colon-delimited notation. When the supplied server argument is a

hostname, ddiigg resolves that name before querying that name server. If no server argument is provided, ddiigg consults /etc/resolv.conf and queries the name servers listed there. The reply from the name server that responds is displayed. nnaammee is the name of the resource record that is to be looked up. ttyyppee

indicates what type of query is required - ANY, A, MX, SIG, etc.

type can be any valid query type. If no type argument is supplied, ddiigg will perform a lookup for an A record. OOPPTTIIOONNSS

The -bb option sets the source IP address of the query to address. This

must be a valid address on one of the host's network interfaces or "0.0.0.0" or "::". An optional port may be specified by appending

"#"

The default query class (IN for internet) is overridden by the -cc

option. class is any valid class, such as HS for Hesiod records or CH for Chaosnet records.

The -ff option makes ddiigg operate in batch mode by reading a list of

lookup requests to process from the file filename. The file contains a number of queries, one per line. Each entry in the file should be organized in the same way they would be presented as queries to ddiigg

using the command-line interface.

The -mm option enables memory usage debugging.

If a non-standard port number is to be queried, the -pp option is used.

port# is the port number that ddiigg will send its queries instead of the

standard DNS port number 53. This option would be used to test a name

server that has been configured to listen for queries on a non-standard

port number.

The -44 option forces ddiigg to only use IPv4 query transport. The -66

option forces ddiigg to only use IPv6 query transport.

The -tt option sets the query type to type. It can be any valid query

type which is supported in BIND 9. The default query type is "A",

unless the -xx 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, type is set to ixfr=N. The incremental zone transfer will contain the changes made to the zone since the serial number in the zone's SOA record was N.

Reverse lookups - mapping addresses to names - are simplified by the

-xx option. addr is an IPv4 address in dotted-decimal notation, or a

colon-delimited IPv6 address. When this option is used, there is no

need to provide the name, class and type arguments. ddiigg automatically

performs a lookup for a name like 11.12.13.10.in-addr.arpa and sets the

query type and class to PTR and IN respectively. By default, IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

To use the older RFC1886 method using the IP6.INT domain specify the -ii

option. Bit string labels (RFC2874) are now experimental and are not attempted. To sign the DNS queries sent by ddiigg and their responses using

transaction signatures (TSIG), specify a TSIG key file using the -kk

option. You can also specify the TSIG key itself on the command line

using the -yy option; name is the name of the TSIG key and key is the

actual key. The key is a base-64 encoded string, typically generated by

ddnnsssseecc-kkeeyyggeenn(8). Caution should be taken when using the -yy option on

multi-user systems as the key can be visible in the output from ppss(1 )

or in the shell's history file. When using TSIG authentication with ddiigg, the name server that is queried needs to know the key and algorithm that is being used. In BIND, this is done by providing appropriate kkeeyy and sseerrvveerr statements in named.conf. QQUUEERRYY OOPPTTIIOONNSS ddiigg provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set or reset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout and retry strategies. Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form ++kkeeyywwoorrdd==vvaalluuee. The query options are: ++[[nnoo]]ttccpp Use [do not use] TCP when querying name servers. The default behavior is to use UDP unless an AXFR or IXFR query is requested, in which case a TCP connection is used. ++[[nnoo]]vvcc Use [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". ++[[nnoo]]iiggnnoorree Ignore truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed. ++ddoommaaiinn==ssoommeennaammee Set the search list to contain the single domain somename, as if specified in a ddoommaaiinn directive in /etc/resolv.conf, and enable search list processing as if the +search option were given. ++[[nnoo]]sseeaarrcchh Use [do not use] the search list defined by the searchlist or domain directive in resolv.conf (if any). The search list is not used by default. ++[[nnoo]]ddeeffnnaammee Deprecated, treated as a synonym for +[no]search ++[[nnoo]]aaaaoonnllyy Sets the "aa" flag in the query. ++[[nnoo]]aaaaffllaagg A synonym for +[no]aaonly. ++[[nnoo]]aaddffllaagg Set [do not set] the AD (authentic data) bit in the query. The AD bit currently has a standard meaning only in responses, not in queries, but the ability to set the bit in the query is provided for completeness. ++[[nnoo]]ccddffllaagg Set [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses. ++[[nnoo]]ccll Display [do not display] the CLASS when printing the record. ++[[nnoo]]ttttlliidd Display [do not display] the TTL when printing the record. ++[[nnoo]]rreeccuurrssee Toggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means ddiigg normally sends recursive queries. Recursion is automatically disabled when the +nssearch or +trace query options are used. ++[[nnoo]]nnsssseeaarrcchh When this option is set, ddiigg attempts to find the authoritative name servers for the zone containing the name being looked up and display the SOA record that each name server has for the zone. ++[[nnoo]]ttrraaccee Toggle 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, ddiigg makes iterative queries to resolve the name being looked up. It will follow referrals from the root servers, showing the answer from each server that was used to resolve the lookup. ++[[nnoo]]ccmmdd Toggles the printing of the initial comment in the output identifying the version of ddiigg and the query options that have been applied. This comment is printed by default. ++[[nnoo]]sshhoorrtt Provide a terse answer. The default is to print the answer in a verbose form. ++[[nnoo]]iiddeennttiiffyy Show [or do not show] the IP address and port number that supplied the answer when the +short option is enabled. If short form answers are requested, the default is not to show the source address and port number of the server that provided the answer. ++[[nnoo]]ccoommmmeennttss Toggle the display of comment lines in the output. The default is to print comments. ++[[nnoo]]ssttaattss This query option toggles the printing of statistics: when the query was made, the size of the reply and so on. The default behavior is to print the query statistics. ++[[nnoo]]qqrr Print [do not print] the query as it is sent. By default, the query is not printed. ++[[nnoo]]qquueessttiioonn Print [do not print] the question section of a query when an answer is returned. The default is to print the question section as a comment. ++[[nnoo]]aannsswweerr Display [do not display] the answer section of a reply. The default is to display it. ++[[nnoo]]aauutthhoorriittyy Display [do not display] the authority section of a reply. The default is to display it. ++[[nnoo]]aaddddiittiioonnaall Display [do not display] the additional section of a reply. The default is to display it. ++[[nnoo]]aallll Set or clear all display flags. ++ttiimmee==TT Sets 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 a query timeout of 1 second being applied. ++ttrriieess==TT Sets 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, the number of tries is silently rounded up to 1. ++rreettrryy==TT Sets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query. ++nnddoottss==DD Set the number of dots that have to appear in name to D for it to be considered absolute. The default value is that defined using the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relative names and will be searched for in the domains listed in the sseeaarrcchh or ddoommaaiinn directive in /etc/resolv.conf. ++bbuuffssiizzee==BB Set the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0 respectively. Values outside this range are rounded up or down appropriately. ++[[nnoo]]mmuullttiilliinnee

Print records like the SOA records in a verbose multi-line format

with human-readable comments. The default is to print each record

on a single line, to facilitate machine parsing of the ddiigg output. ++[[nnoo]]ffaaiill Do not try the next server if you receive a SERVFAIL. The default is to not try the next server which is the reverse of normal stub resolver behavior. ++[[nnoo]]bbeesstteeffffoorrtt Attempt to display the contents of messages which are malformed. The default is to not display malformed answers. ++[[nnoo]]ddnnsssseecc Requests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query. ++[[nnoo]]ssiiggcchhaassee

Chase DNSSEC signature chains. Requires dig be compiled with

-DDIGSIGCHASE.

++ttrruusstteedd-kkeeyy==########

Specifies a file containing trusted keys to be used with ++ssiiggcchhaassee. Each DNSKEY record must be on its own line.

If not specified ddiigg will look for /etc/trusted-key.key then

trusted-key.key in the current directory.

Requires dig be compiled with -DDIGSIGCHASE.

++[[nnoo]]ttooppddoowwnn

When chasing DNSSEC signature chains perform a top-down validation.

Requires dig be compiled with -DDIGSIGCHASE.

MMUULLTTIIPPLLEE QQUUEERRIIEESS The BIND 9 implementation of ddiigg supports specifying multiple queries

on the command line (in addition to supporting the -ff batch file

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 of the

standard options and flags, the name to be looked up, an optional query type and class and any query options that should be applied 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 precede the first tuple of name, class, type, options, flags, and query options supplied on the command line. Any global query options (except the ++[[nnoo]]ccmmdd

option) can be overridden by a query-specific set of query options. For

example:

dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr

shows how ddiigg could be used from the command line to make three lookups: an ANY query for www.isc.org, a reverse lookup of 127.0.0.1 and a query for the NS records of isc.org. A global query option of +qr is applied, so that ddiigg shows the initial query it made for each lookup. The final query has a local query option of +noqr which means that ddiigg will not print the initial query when it looks up the NS records for isc.org. FILES /etc/resolv.conf

${HOME}/.digrc

BUGS

There are probably too many query options. COPYRIGHT

BIND9 Jun 30, 2000 DIG(1)