NSLOOKUP(1) BIND9 NSLOOKUP(1)
nslookup - query Internet name servers interactively
nslookup [-option] [name | -] [server]
Nslookup is a program to query Internet domain name servers. Nslookup
has two modes: interactive and non-interactive. Interactive mode allows
the user to query name servers for information about various hosts and
domains or to print a list of hosts in a domain. Non-interactive mode
is used to print just the name and requested information for a host or
Interactive mode is entered in the following cases:
1. when no arguments are given (the default name server will be used)
2. when the first argument is a hyphen (-) and the second argument is
the host name or Internet address of a name server.
Non-interactive mode is used when the name or Internet address of the
host to be looked up is given as the first argument. The optional
second argument specifies the host name or address of a name server.
Options can also be specified on the command line if they precede the
arguments and are prefixed with a hyphen. For example, to change the
default query type to host information, and the initial timeout to 10
nslookup -query=hinfo -timeout=10
The -version option causes nslookup to print the version number and
Look up information for host using the current default server or
using server, if specified. If host is an Internet address and the
query type is A or PTR, the name of the host is returned. If host
is a name and does not have a trailing period, the search list is
used to qualify the name.
To look up a host not in the current domain, append a period to the
Change the default server to domain; lserver uses the initial
server to look up information about domain, while server uses the
current default server. If an authoritative answer can't be found,
the names of servers that might have the answer are returned.
Exits the program.
This command is used to change state information that affects the
lookups. Valid keywords are:
Prints the current values of the frequently used options to
set. Information about the current default server and host is
Change the query class to one of:
the Internet class
the Chaos class
the Hesiod class
The class specifies the protocol group of the information.
(Default = IN; abbreviation = cl)
Turn on or off the display of the full response packet and any
intermediate response packets when searching.
(Default = nodebug; abbreviation = [no]deb)
Turn debugging mode on or off. This displays more about what
nslookup is doing.
(Default = nod2)
Sets the search list to name.
If the lookup request contains at least one period but doesn't
end with a trailing period, append the domain names in the
domain search list to the request until an answer is received.
(Default = search)
Change the default TCP/UDP name server port to value.
(Default = 53; abbreviation = po)
Change the type of the information query.
(Default = A and then AAAA; abbreviations = q, ty)
Note: It is only possible to specify one query type, only the
default behavior looks up both when an alternative is not
Tell the name server to query other servers if it does not have
(Default = recurse; abbreviation = [no]rec)
Set the number of dots (label separators) in a domain that will
disable searching. Absolute names always stop searching.
Set the number of retries to number.
Change the initial timeout interval for waiting for a reply to
Always use a virtual circuit when sending requests to the
(Default = novc)
Try the next nameserver if a nameserver responds with SERVFAIL
or a referral (nofail) or terminate query (fail) on such a
(Default = nofail)
nslookup returns with an exit status of 1 if any query failed, and 0
If nslookup has been built with IDN (internationalized domain name)
support, it can accept and display non-ASCII domain names. nslookup
appropriately converts character encoding of domain name before sending
a request to DNS server or displaying a reply from the server. If you'd
like to turn off the IDN support for some reason, define the
IDN_DISABLE environment variable. The IDN support is disabled if the
variable is set when nslookup runs or when the standard output is not a
dig(1), host(1), named(8).
Internet Systems Consortium, Inc.
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ISC 2014-01-24 NSLOOKUP(1)
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