1NSLOOKUP(1)                         BIND 9                         NSLOOKUP(1)
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NAME

6       nslookup - query Internet name servers interactively
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SYNOPSIS

9       nslookup [-option] [name | -] [server]
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DESCRIPTION

12       nslookup  is a program to query Internet domain name servers.  nslookup
13       has two modes: interactive and non-interactive. Interactive mode allows
14       the  user to query name servers for information about various hosts and
15       domains or to print a list of hosts in a domain.  Non-interactive  mode
16       prints just the name and requested information for a host or domain.
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ARGUMENTS

19       Interactive mode is entered in the following cases:
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21       a. when no arguments are given (the default name server is used);
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23       b. when  the  first argument is a hyphen (-) and the second argument is
24          the host name or Internet address of a name server.
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26       Non-interactive mode is used when the name or Internet address  of  the
27       host  to be looked up is given as the first argument. The optional sec‐
28       ond argument specifies the host name or address of a name server.
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30       Options can also be specified on the command line if they  precede  the
31       arguments  and  are  prefixed with a hyphen. For example, to change the
32       default query type to host information, with an initial timeout  of  10
33       seconds, type:
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35          nslookup -query=hinfo  -timeout=10
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37       The -version option causes nslookup to print the version number and im‐
38       mediately exit.
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INTERACTIVE COMMANDS

41       host [server]
42              This command looks up information for host using the current de‐
43              fault server or using server, if specified. If host is an Inter‐
44              net address and the query type is A or PTR, the name of the host
45              is  returned. If host is a name and does not have a trailing pe‐
46              riod (.), the search list is used to qualify the name.
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48              To look up a host not in the current domain, append a period  to
49              the name.
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51       server domain | lserver domain
52              These commands change the default server to domain; lserver uses
53              the initial server to look up information  about  domain,  while
54              server  uses the current default server. If an authoritative an‐
55              swer cannot be found, the names of servers that might  have  the
56              answer are returned.
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58       root   This command is not implemented.
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60       finger This command is not implemented.
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62       ls     This command is not implemented.
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64       view   This command is not implemented.
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66       help   This command is not implemented.
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68       ?      This command is not implemented.
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70       exit   This command exits the program.
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72       set keyword[=value]
73              This  command  is  used to change state information that affects
74              the lookups. Valid keywords are:
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76              all    This keyword prints the current values of the  frequently
77                     used  options  to  set. Information about the current de‐
78                     fault server and host is also printed.
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80              class=value
81                     This keyword changes the query class to one of:
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83                     IN     the Internet class
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85                     CH     the Chaos class
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87                     HS     the Hesiod class
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89                     ANY    wildcard
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91                     The class specifies the protocol group  of  the  informa‐
92                     tion.  The  default is IN; the abbreviation for this key‐
93                     word is cl.
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95              nodebug
96                     This keyword turns on or off the display of the full  re‐
97                     sponse  packet,  and  any  intermediate response packets,
98                     when searching. The default for this keyword is  nodebug;
99                     the abbreviation for this keyword is [no]deb.
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101              nod2   This  keyword  turns  debugging mode on or off. This dis‐
102                     plays more about what nslookup is doing. The  default  is
103                     nod2.
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105              domain=name
106                     This keyword sets the search list to name.
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108              nosearch
109                     If  the  lookup request contains at least one period, but
110                     does not end with a trailing period, this keyword appends
111                     the domain names in the domain search list to the request
112                     until an answer is received. The default is search.
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114              port=value
115                     This keyword changes the default TCP/UDP name server port
116                     to  value from its default, port 53. The abbreviation for
117                     this keyword is po.
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119              querytype=value | type=value
120                     This keyword changes the type of the information query to
121                     value.  The  defaults  are A and then AAAA; the abbrevia‐
122                     tions for these keywords are q and ty.
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124                     Please note that it is only possible to specify one query
125                     type. Only the default behavior looks up both when an al‐
126                     ternative is not specified.
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128              norecurse
129                     This keyword tells the name server to query other servers
130                     if  it  does not have the information. The default is re‐
131                     curse; the abbreviation for this keyword is [no]rec.
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133              ndots=number
134                     This keyword sets the number of dots  (label  separators)
135                     in  a  domain that disables searching. Absolute names al‐
136                     ways stop searching.
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138              retry=number
139                     This keyword sets the number of retries to number.
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141              timeout=number
142                     This keyword changes the initial timeout interval to wait
143                     for a reply to number, in seconds.
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145              novc   This  keyword indicates that a virtual circuit should al‐
146                     ways be used when sending requests to the  server.   novc
147                     is the default.
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149              nofail This  keyword  tries  the next nameserver if a nameserver
150                     responds with SERVFAIL or a referral (nofail), or  termi‐
151                     nates the query (fail) on such a response. The default is
152                     nofail.
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RETURN VALUES

155       nslookup returns with an exit status of 1 if any query  failed,  and  0
156       otherwise.
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IDN SUPPORT

159       If  nslookup  has  been  built with IDN (internationalized domain name)
160       support, it can accept and display non-ASCII domain names. nslookup ap‐
161       propriately converts character encoding of a domain name before sending
162       a request to a DNS server or displaying a reply from  the  server.   To
163       turn  off IDN support, define the IDN_DISABLE environment variable. IDN
164       support is disabled if the variable is set when nslookup runs, or  when
165       the standard output is not a tty.
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FILES

168       /etc/resolv.conf
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SEE ALSO

171       dig(1), host(1), named(8).
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AUTHOR

174       Internet Systems Consortium
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177       2023, Internet Systems Consortium
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1829.18.11                                                            NSLOOKUP(1)
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