The configuration options of NSLOOKUP determine the operation
and results of your name server queries. These options can be specified
in command-mode queries, interactive-mode queries, or in the user_id.NSLOOKUP.ENV
data set. When you include NSLOOKUP options with the initial NSLOOKUP
command the (-) operand must immediately precede
the option. If you specify NSLOOKUP options while in interactive mode,
the SET subcommand must precede the option. Specifying NSLOOKUP options
in the user_id.NSLOOKUP.ENV data set is
optional. Use the SET subcommand before the option if you want to
reset the option value. The (-) operand is
not valid preceding options in the user_id.NSLOOKUP.ENV
data set.
For example, to specify a name server (NS) type record
lookup for the domain name
fourex.oz in command mode
you enter:
nslookup -querytype=ns fourex.oz
To submit the same request using interactive mode enter
the following sequence:
nslookup
set querytype=ns
fourex.oz
To make
querytype of NS a default option
for your NSLOOKUP commands, place one of the following statements
in the
user_id.NSLOOKUP.ENV data set:
- set querytype=ns
- querytype=ns
The optional data set user_id.NSLOOKUP.ENV.
contains only NSLOOKUP options and defines the NSLOOKUP defaults.
If the user_id.NSLOOKUP.ENV data set exists,
the NSLOOKUP options are read from the data set and executed before
any queries are made. You must enter each option on a separate line.
Blank lines are ignored.
The following example shows the contents of the
user_id.NSLOOKUP.ENV
data set:
set domain=powers.oz
querytype=HINFO
set norecurse
vc
Option
|--+-all---------------------+----------------------------------|
+-class--=--class---------+
| .-nod2-. |
+-+-d2---+----------------+
| .-nodebug-. |
+-+-debug---+-------------+
| .-nodefname-. |
+-+-defname---+-----------+
+-domain--=--name---------+
| .-noignoretc-. |
+-+-ignoretc---+----------+
| .-53------------. |
+-+-port--=--port-+-------+
| .-A------------------. |
+-+-querytype--=--type-+--+
| .-recurse---. |
+-+-norecurse-+-----------+
+-retry--=--limit---------+
+-root--=--name-----------+
| .-search---. |
+-+-nosearch-+------------+
| .-⁄------. |
| V | |
+-srchlist--=----domain-+-+
+-timeout--=--interval----+
| .-novc-. |
'-+-vc---+----------------'
- all
- Enables
you to print the current values of the internal state variables. This
option does not alter the internal state of NSLOOKUP.
- class=class
- Sets
the class of information returned by queries. The class must be identified
by its mnemonic. The minimum abbreviation for this option is cl.
- d2
- Directs
NSLOOKUP to enable extra debugging mode. Using d2 also
enables debug mode.
Note: To obtain all alias names for a host when
using reverse query, you must set the d2 option.
- nod2
- Directs
NSLOOKUP to disable extra debugging mode. The default is nod2.
- debug
- Directs
NSLOOKUP to print debugging information for each query and its corresponding
response. The minimum abbreviation is deb and nodeb.
- nodebug
- Directs
NSLOOKUP to not print debugging information for each query and its
corresponding response. This option also disables d2.
The minimum abbreviation is nodeb. This
is the default.
- defname
- Directs
NSLOOKUP to append the default domain name to an unqualified domain
name in a query. This value is the default. If the search list is
also enabled, then the domain names specified in the search list will
also be appended until a query is resolved or until no more domain
names are left in the search list.
The default domain name is initially
obtained from the TCPIP.DATA data set, but can be changed using the
domain=name option. The minimum abbreviation
for this option is def.
- nodefname
- Directs
NSLOOKUP to not append the default domain name to an unqualified domain
name in a query.
If you specify this option, the domain name specified
in the query is passed to the server without modification. The search
list will not be used, even if it is enabled. The minimum abbreviation
for this option is nodef.
- domain=name
- Sets the default domain name to name.
Initially, the default domain name is obtained from the TCPIP.DATA
data set. The validity of name is not verified.
This option also updates the search list. The search list contains
the domain specified and the parents of the default domain if it has
at least two components in its name. For example, if the default domain
is wurrup.forex.oz, the search list contains wurrup.forex.oz and forex.oz.
Use the SET srchlist command to specify
a different search list. The minimum abbreviation for this option
is do.
- ignoretc
- Directs NSLOOKUP on the handling of truncated responses. The name
server indicates, in the response header, that the complete query
response did not fit into a single UDP packet and has been truncated.
Specifying ignoretc directs NSLOOKUP
to ignore the truncation condition when it is set in the response
by the name server.
NSLOOKUP does not handle responses greater
than 512 characters in length. Responses greater than 512 characters
are truncated and the internal truncation flag is set. This condition
is revealed only when the debug option is
enabled. The minimum abbreviation for this option is ig.
- noignorectc
- Directs NSLOOKUP to automatically retry the query using a TCP
connection when a response is sent with the truncation indicator set.
This is the default. The minimum abbreviation for this option is noig.
- port=port
- Specifies the port number to use when contacting the name server.
The Domain Name System is a well-known service and has been allocated
port 53. NSLOOKUP uses port 53 by default, but the port option enables
you to specify another port to access. The minimum abbreviation for
this option is po.
- querytype=type
- Specifies the type of information returned by queries. The initial
query type is A (address information). See the z/OS Communications Server: IP Configuration
Reference for detailed information about available
query types.
NSLOOKUP cannot generate queries about type NULL.
However, it can accept responses containing resource records of type
NULL. In this case, NSLOOKUP displays the number of bytes returned
in the NULL record. Global queries that return all resource records
for a specific domain name are specified by the wildcard value ANY.
The minimum abbreviation for this option is q.
The
type=type option is accepted by NSLOOKUP
as a synonym for the querytype=type option.
- recurse
- Directs NSLOOKUP to request a recursive query when querying a
name server. The minimum abbreviation for this option is rec.
This is the default.
- norecurse
- Specifies that a recursive query is not returned. The minimum
abbreviation for this option is norec.
- retry=limit
- Specifies the number of times a request is resent. When a request
is sent and the timeout period expires for a response, the request
is resent until the value specified in limit has
been exceeded. The value specified in limit determines
the number of attempts made to contact the name server. The default
value for limit is retrieved from the TCPIP.DATA
data set.
Setting limit to 0 disables
NSLOOKUP from contacting the name server. The result is an error message no
response from server.
The retry algorithm for NSLOOKUP
uses both the limit value and the timeout
period. The minimum abbreviation for this option is ret.
- root=name
- Specifies the name of a root server. The root server is ns.nic.ddn.mil by
default.
- search
- Directs NSLOOKUP to enable the use of a search list. The minimum
abbreviation for this option is sea.
- nosearch
- Directs NSLOOKUP to disable the use of a search list. The minimum
abbreviation for this option is nosea.
- srchlist=[domain⁄domain⁄...]
- Specifies one or up to three domain names to be appended to non-fully-qualified
domain names when attempting to resolve the host name. Each domain
name specified is tried in turn until a match is found or no domain
names are left to try.
This option also directs the default domain
to be set to the first domain name specified in the search list. The
minimum abbreviation for this option is srchl.
- timeout=interval
- Specifies the number of seconds to wait before timing out of a
request. The default for interval is retrieved
from the TCPIP.DATA data set. The minimum abbreviation for this option
is t.
- vc
- Specifies to use a virtual circuit (TCP connection) to transport
queries to the name server or datagrams (UDP). The default is retrieved
from the TCPIP.DATA data set.
- novc
- Specifies to not use a virtual circuit to transport queries to
the name server or datagrams. This option is the default.