3 .\" Copying and distribution of this file, with or without modification,
4 .\" are permitted in any medium without royalty provided the copyright
5 .\" notice and this notice are preserved. This file is offered as-is,
6 .\" without any warranty.
12 .Nd DNS lookup utility
25 is a simple utility for performing DNS lookups. It is normally
26 used to convert names to IP addresses and vice versa.
29 is the domain name that is to be looked up. It can also be a
30 dotted-decimal IPv4 address or a colon-delimited IPv6 address,
33 will by default perform a reverse lookup for that address.
39 prints a short summary of it's usage.
42 is an optional argument which is either a domain name or an IP
43 address of the name server that
45 should query instead of the server or servers listed in
46 .Pa /etc/resolv.conf .
49 is a domain name, system resolver is used to obtain it's address.
52 .Bl -tag -width indent
54 Make a verbose query of type
63 from all of it's authoritative name servers. The list of name
64 servers is obtained via
69 Perform DNS query of class
71 Recognized classes are
81 is a number from 1 to 255). Default is
84 Produce verbose output. This is a synonym for
86 and is provided for backward compatibility.
88 Use IP6.INT domain for reverse lookups of IPv6 addresses (as
89 defined in RFC1886; note that RFC4159 deprecates IP6.INT).
90 By default IP6.ARPA is used.
98 by performing a zone transfer
100 You can combine this option with
102 to print all records, or with
104 to only print specific ones.
106 Consider names with at least this many dots as absolute. That
107 is, try to resolve them directly before consulting
112 .Pa /etc/resolv.conf .
114 Perform non-recursive query to the name server by clearing RD
115 .Pq Dq recursion desired
118 Retry this many times when a query does not receive an answer
119 in time. The default is 1 retry. If
121 is negative or zero, 1 is used instead.
123 Report SERVFAIL responses as they are, do not ignore them.
125 Query name server over TCP. By default UDP is used, except for
129 queries, which require TCP.
131 will also retry UDP queries in TCP mode if the UDP response was
132 truncated (i.e. had TC bit set).
134 Perform DNS query of type
136 which can be any standard query type name
137 .Pq Cm A , CNAME , MX , TXT , No etc ,
144 is a number from 1 to 65535. For
145 .Cm IXFR Pq incremental zone transfer
146 queries the starting serial number can be specified by appending
147 an equal sign followed by the number
148 .Pq e.g. Fl t Cm IXFR Ns =12345678 .
150 The default is to query for
151 .Cm A , AAAA , No and Cm MX
156 options are given (in which case
162 is a valid IP address
163 (in which case reverse lookup using
167 Produce verbose output.
169 Wait forever (or for a very long time) for response from the
172 Wait this many seconds for a reply from name server before timing
175 is negative or zero, value of 1 is used. The default is to wait
176 10 seconds for TCP connections, and 5 seconds for UDP (both are
177 subject to retries, see option
180 Only use IPv4 transport.
182 Only use IPv6 transport.
191 aims to be reasonably compatible with
193 utility from BIND9 distribution, both in supported options and
194 in produced output. Here is a list of known notable differences:
207 Backslashes in domain names are treated especially.
209 The maximum of 255 retries (option
213 Some resource records are formatted differently. For example,
217 records are displayed without spaces in them.
225 are ignored. When multiple
229 commands are present,
233 command, and then all of
237 from BIND9 uses whatever command was specified last.
239 .Sq Pseudosection TSIG
240 is missing from verbose packet output.
243 .An Vitaly Magerya Aq magv@tx97.net