4.3BSD-Reno/share/man/cat8/nslookup.0
NSLOOKUP(8) 1990 NSLOOKUP(8)
NNAAMMEE
nslookup - query Internet name servers interactively
SSYYNNOOPPSSIISS
nnssllooookkuupp [ -_o_p_t_i_o_n ... ] [ _h_o_s_t-_t_o-_f_i_n_d | - [ _s_e_r_v_e_r ]]
DDEESSCCRRIIPPTTIIOONN
_N_s_l_o_o_k_u_p 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
domain.
AARRGGUUMMEENNTTSS
Interactive mode is entered in the following cases:
a) when no arguments are given (the default name server
will be used),
b) 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.
The options listed under the ``set'' command below can be
specified in the .nslookuprc file in the user's home direc-
tory if they are listed one per line. 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 seconds, type:
nslookup -query=hinfo -timeout=10
IINNTTEERRAACCTTIIVVEE CCOOMMMMAANNDDSS
Commands may be interrupted at any time by typing a
control-C. To exit, type a control-D (EOF) or type exit.
The command line length must be less than 256 characters.
To treat a built-in command as a host name, precede it with
an escape character (\). NN..BB.. an unrecognized command will
be interpreted as a host name.
_h_o_s_t [_s_e_r_v_e_r]
Look up information for _h_o_s_t using the current default
server or using _s_e_r_v_e_r if specified. If _h_o_s_t is an
Internet address and the query type is A or PTR, the
Printed 7/27/90 June 1
NSLOOKUP(8) 1990 NSLOOKUP(8)
name of the host is returned. If _h_o_s_t is a name and
does not have a trailing period, the default domain
name is appended to the name. (This behavior depends on
the state of the sseett options ddoommaaiinn, ssrrcchhlliisstt, ddeeffnnaammee,
and sseeaarrcchh). To look up a host not in the current
domain, append a period to the name.
sseerrvveerr _d_o_m_a_i_n
llsseerrvveerr _d_o_m_a_i_n
Change the default server to _d_o_m_a_i_n. LLsseerrvveerr uses the
initial server to look up information about _d_o_m_a_i_n
while sseerrvveerr uses the current default server. If an
authoritative answer can't be found, the names of
servers that might have the answer are returned.
rroooott Changes the default server to the server for the root
of the domain name space. Currently, the host
ns.nic.ddn.mil is used. (This command is a synonym for
llsseerrvveerr nnss..nniicc..ddddnn..mmiill..) The name of the root server
can be changed with the sseett rroooott command.
ffiinnggeerr [_n_a_m_e] [>> _f_i_l_e_n_a_m_e]
ffiinnggeerr [_n_a_m_e] [>>>> _f_i_l_e_n_a_m_e]
Connects with the finger server on the current host.
The current host is defined when a previous lookup for
a host was successful and returned address information
(see the sseett qquueerryyttyyppee==AA command). _N_a_m_e is optional. >>
and >>>> can be used to redirect output in the usual
manner.
llss [_o_p_t_i_o_n] _d_o_m_a_i_n [>> _f_i_l_e_n_a_m_e]
llss [_o_p_t_i_o_n] _d_o_m_a_i_n [>>>> _f_i_l_e_n_a_m_e]
List the information available for _d_o_m_a_i_n, optionally
creating or appending to _f_i_l_e_n_a_m_e. The default output
contains host names and their Internet addresses.
_O_p_t_i_o_n can be one of the following:
--tt _q_u_e_r_y_t_y_p_e
lists all records of the specified type (see
_q_u_e_r_y_t_y_p_e below).
--aa lists aliases of hosts in the domain. synonym for
--tt CCNNAAMMEE.
--dd lists all records for the domain. synonym for
--tt AANNYY.
--hh lists CPU and operating system information for the
Printed 7/27/90 June 2
NSLOOKUP(8) 1990 NSLOOKUP(8)
domain. synonym for --tt HHIINNFFOO.
--ss lists well-known services of hosts in the domain.
synonym for --tt WWKKSS.
When output is directed to a file, hash marks are
printed for every 50 records received from the server.
vviieeww _f_i_l_e_n_a_m_e
Sorts and lists the output of previous llss command(s)
with _m_o_r_e(1).
hheellpp
?? Prints a brief summary of commands.
eexxiitt Exits the program.
sseett _k_e_y_w_o_r_d[=_v_a_l_u_e]
This command is used to change state information that
affects the lookups. Valid keywords are:
aallll Prints the current values of the frequently-used
options to sseett. Information about the current
default server and host is also printed.
ccllaassss==_v_a_l_u_e
Change the query class to one of:
IN the Internet class.
CHAOS the Chaos class.
HESIOD the MIT Athena Hesiod class.
ANY wildcard (any of the above).
The class specifies the protocol group of the
information.
(Default = IN, abbreviation = cl)
[[nnoo]]ddeebbuugg
Turn debugging mode on. A lot more information is
printed about the packet sent to the server and
the resulting answer.
(Default = nodebug, abbreviation = [no]deb)
[[nnoo]]dd22
Printed 7/27/90 June 3
NSLOOKUP(8) 1990 NSLOOKUP(8)
Turn exhaustive debugging mode on. Essentially
all fields of every packet are printed.
(Default = nod2)
ddoommaaiinn==_n_a_m_e
Change the default domain name to _n_a_m_e. The
default domain name is appended to a lookup
request depending on the state of the ddeeffnnaammee and
sseeaarrcchh options. The domain search list contains
the parents of the default domain if it has at
least two components in its name. For example, if
the default domain is CC.Berkeley.EDU, the search
list is CC.Berkeley.EDU and Berkeley.EDU. Use the
sseett ssrrcchhlliisstt command to specify a different list.
Use the sseett aallll command to display the list.
(Default = value from hostname, /etc/resolv.conf
or LOCALDOMAIN, abbreviation = do)
ssrrcchhlliisstt==_n_a_m_e_1/_n_a_m_e_2/...
Change the default domain name to _n_a_m_e_1 and the
domain search list to _n_a_m_e_1, _n_a_m_e_2, etc. A maximum
of 6 names separated by slashes (/) can be speci-
fied. For example,
set srchlist=lcs.MIT.EDU/ai.MIT.EDU/MIT.EDU
sets the domain to lcs.MIT.EDU and the search list
to the three names. This command overrides the
default domain name and search list of the sseett
ddoommaaiinn command. Use the sseett aallll command to
display the list.
(Default = value based on hostname,
/etc/resolv.conf or LOCALDOMAIN, abbreviation =
srchl)
[[nnoo]]ddeeffnnaammee
If set, append the default domain name to a
single-component lookup request (i.e., one that
does not contain a period).
(Default = defname, abbreviation = [no]def)
[[nnoo]]sseeaarrcchh
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, abbreviation = [no]sea)
ppoorrtt==_v_a_l_u_e
Change the default TCP/UDP name server port to
_v_a_l_u_e.
(Default = 53, abbreviation = po)
qquueerryyttyyppee==_v_a_l_u_e
Printed 7/27/90 June 4
NSLOOKUP(8) 1990 NSLOOKUP(8)
ttyyppee==_v_a_l_u_e
Change the type of information query to one of:
A the host's Internet address.
CNAME the canonical name for an alias.
HINFO the host CPU and operating system type.
MINFO the mailbox or mail list information.
MX the mail exchanger.
NS the name server for the named zone.
PTR the host name if the query is an Inter-
net address, otherwise the pointer to
other information.
SOA the domain's ``start-of-authority''
information.
TXT the text information.
UINFO the user information.
WKS the supported well-known services.
Other types (ANY, AXFR, MB, MD, MF, NULL) are
described in the RFC-1035 document.
(Default = A, abbreviations = q, ty)
[[nnoo]]rreeccuurrssee
Tell the name server to query other servers if it
does not have the information.
(Default = recurse, abbreviation = [no]rec)
rreettrryy==_n_u_m_b_e_r
Set the number of retries to _n_u_m_b_e_r. When a reply
to a request is not received within a certain
amount of time (changed with sseett ttiimmeeoouutt), the
timeout period is doubled and the request is
resent. The retry value controls how many times a
request is resent before giving up.
(Default = 4, abbreviation = ret)
rroooott==_h_o_s_t
Change the name of the root server to _h_o_s_t. This
affects the rroooott command.
(Default = ns.nic.ddn.mil., abbreviation = ro)
ttiimmeeoouutt==_n_u_m_b_e_r
Printed 7/27/90 June 5
NSLOOKUP(8) 1990 NSLOOKUP(8)
Change the initial timeout interval for waiting
for a reply to _n_u_m_b_e_r seconds. Each retry doubles
the timeout period.
(Default = 5 seconds, abbreviation = ti)
[[nnoo]]vvcc
Always use a virtual circuit when sending requests
to the server.
(Default = novc, abbreviation = [no]v)
[[nnoo]]iiggnnoorreettcc
Ignore packet truncation errors.
(Default = noignoretc, abbreviation = [no]ig)
DDIIAAGGNNOOSSTTIICCSS
If the lookup request was not successful, an error message
is printed. Possible errors are:
Timed out
The server did not respond to a request after a certain
amount of time (changed with sseett ttiimmeeoouutt==_v_a_l_u_e) and a
certain number of retries (changed with sseett
rreettrryy==_v_a_l_u_e).
No response from server
No name server is running on the server machine.
No records
The server does not have resource records of the
current query type for the host, although the host name
is valid. The query type is specified with the sseett
qquueerryyttyyppee command.
Non-existent domain
The host or domain name does not exist.
Connection refused
Network is unreachable
The connection to the name or finger server could not
be made at the current time. This error commonly
occurs with llss and ffiinnggeerr requests.
Server failure
The name server found an internal inconsistency in its
database and could not return a valid answer.
Refused
The name server refused to service the request.
Format error
The name server found that the request packet was not
in the proper format. It may indicate an error in
Printed 7/27/90 June 6
NSLOOKUP(8) 1990 NSLOOKUP(8)
_n_s_l_o_o_k_u_p.
FFIILLEESS
/etc/resolv.conf initial domain name and
name server addresses.
$HOME/.nslookuprc user's initial options.
/usr/share/misc/nslookup.help summary of commands.
EENNVVIIRROONNMMEENNTT
HOSTALIASES file containing host aliases.
LOCALDOMAIN overrides default domain.
SSEEEE AALLSSOO
resolver(3), resolver(5), named(8),
RFC-1034 ``Domain Names - Concepts and Facilities''
RFC-1035 ``Domain Names - Implementation and Specifica-
tion''
AAUUTTHHOORR
Andrew Cherenson
Printed 7/27/90 June 7