Use the NSLOOKUP command to issue multiple queries in interactive mode. In interactive mode, an initial query is made to the selected name server to verify that the server is accessible. All subsequent interactive queries are sent to that server unless you specify another server using the server or lserver options.
Format
>>-NSLOOKUP--+-----------------+--+-------------------+---------> | .-------------. | +- - server_name----+ | V | | '- - server_address-' '---| -Option |-+-' .----------------. V | >--Enter----| SubCommand |-+----------------------------------->< SubCommand |--+-+-domain_name----+--+----------------+--+-----------------------+-+--Enter--| | '-domain_address-' +-server_name----+ '-+->--+--data_set_name-' | | '-server_address-' '->>-' | +-exit--------------------------------------------------------------+ +-finger--loginname--+-----------------------+----------------------+ | '-+->--+--data_set_name-' | | '->>-' | +-+-help-+----------------------------------------------------------+ | '-?----' | +-ls--+----------------+--domain--+-----------------------+---------+ | +- -a -----------+ '-+->--+--data_set_name-' | | +- -d------------+ '->>-' | | +- -h------------+ | | +- -s------------+ | | '- -t--+-------+-' | | '- type-' | +-lserver--+-name----+----------------------------------------------+ | '-address-' | +-root--------------------------------------------------------------+ +-server--+-name----+-----------------------------------------------+ | '-address-' | +-set--| Option |---------------------------------------------------+ '-view--data_set_name-----------------------------------------------'
Parameters
Queries processed by NSLOOKUP that specify an address can give unexpected results. If the current query type is address (A) or domain-name pointer (PTR), NSLOOKUP generates a PTR type query for the specified address in the in-addr.arpa domain. This returns PTR records which define the host name for the specified address. If the current query type is neither of these two types, a query is performed using the current query type, with the domain name specified as the address given.
Text that does not conform to the defined options and follows the preceding syntax is treated as a domain query. NSLOOKUP does not issue a query for a domain name if the name is unqualified and is the same as one of the defined options.
- -Option
- For a description of the NSLOOKUP options, see NSLOOKUP options.
- address
- Specifies the IP address of the server.
- data_set_name
-
Output can be placed in a data set for later viewing by specifying data_set_name. The > data_set_name option places the output in data_set_name and overwrites the contents, if any, of the data set. The >> data_set_name option places the output in data_set_name and appends it to the contents, if any, of the data set. There must be at least one space before and after the > or >> symbol.
- domain_address
- Reverses the components of the address and generates a pointer type (PTR) query to the name server for the in-addr.arpa domain mapping of the address to a domain name.
- domain_name
- Queries
the name server for information about the current query type of domain_name.
The default query type is A (address query).
If the domain name starts with an underscore (_), you must prefix the domain name with the escape character (\).
- exit
- Exits from NSLOOKUP interactive mode.
- finger parms
- Extracts
information from the finger server of the node found in the last address
query. By default, this command returns a list of logged-in users
for the node last found. You can find information about a particular
user by specifying the loginname of the
user as a parameter.
An error occurs if the preceding subcommand was not a successful address query or finger operation. If the current host is not defined, querying the name server defines that name server to be the current host for a subsequent finger operation.
The finger option expects that the finger server is operating on the node found. An error occurs if the server is not operating or the node cannot be reached.
- help or ?
- Displays a brief summary of commands.
- loginname
- The logged-in user name. The loginname variable is case sensitive and must be specified in the same case (upper or lower) as that used by the host.
- ls parms
- Lists
various information available for the domain. By default, the IP address
of each node in the domain is listed. To select resource records other than the default, specify one of the following options:
- -a
- CNAME
- -d
- ALL
- -h
- HINFO
- -s
- WKS
- -t [type]
- Retrieves the resource record type specified in type.
If no record type is specified with the -t option,
the current default type is used.
If type is ns, up to 24 characters of the returned DNS name is displayed. The UNIX onslookup/nslookup command can be used to display the entire DNS name.
See the z/OS Communications Server: IP Configuration Reference for detailed information about valid query types.
The ls command expects the domain name specified in domain to be a zone. If the domain name specified refers to a host, an error message is printed and no information is given. This command should create a virtual circuit (TCP connection) with the current name server to service the request. An error message is printed if the virtual circuit cannot be established.
A # symbol is displayed at the terminal as every 50 lines are written to the data set to indicate the command is still executing.
- lserver parms
- Changes
the current server. If server_name is specified,
the IP address of server_name is determined
using the initial server defined at command invocation.
An error occurs if the domain name cannot be mapped to an IP address. This option does not ensure that a name server can be reached at the node specified; it simply changes a local variable storing the address of the default name server.
- name
- Specifies the name of the server.
- root
- Changes
the current server address to the address of the root server. The
root server is ns.nic.ddn.mil by default, but can
be changed using the root=name SET subcommand.
This command is equivalent to lserver name.
An error occurs if the name of the root server cannot be mapped to an IP address. This option does not ensure that a name server can be reached at the node specified; it simply changes a local variable storing the address of the default name server.
- server_address
- Specifies the IP address of the name server to be queried other than the default name server. A query for the address in the in-addr.arpa domain is initially made to the default name server to map the IP address to a domain name for the server.
- server_name
- Directs the default name server to map server_name to an IP address and then use the name server at that IP address.
- server parms
- Changes
the current server. If name is specified,
the IP address of name is determined using
the current server.
An error occurs if the domain name cannot be mapped to an IP address. This option does not ensure that a name server can be reached at the address; it simply changes a local variable storing the address of the default name server.
- set option
- Changes internal state information values. See NSLOOKUP options for a description of the options.
- view data_set_name
- Sorts and lists the contents of data_set_name one screen at a time. An error occurs if the data set does not exist.
Usage
- You can query by entering the domain name of the node or subnetwork
for which information is required. Define the data type of information
to be retrieved using the SET querytype= option.
You can define only one type of resource record for a domain name
in a single query, unless the wildcard query type of ANY has been
set. If an IP address is given instead of a domain name, a query for
the address in the in-addr.arpa domain is made to
map the IP address to a domain name. The domain name or address for the query can be followed by the domain name or IP address of a name server to contact for the query. If this is not specified, the current name server is used. For example, entering:
queries the name server on wurrup.fourex.oz for information about the node toolah. When specifying domain names that include periods, the trailing period (indicating a fully qualified domain name) is optional. NSLOOKUP deletes the trailing period if it is present. If you are specifying a root domain, the domain name must have two trailing periods. For example, specify mynode.. when the node mynode is in the root domain.toolah wurrup.fourex.oz - The name server often requires a fully qualified domain name for queries. However, NSLOOKUP enables the specification of a default subnetwork domain using the SET domain= option, with the initial default obtained from the TCPIP.DATA data set. When the defname flag is enabled using the SET defname option, the default domain name specified by SET domain= is appended to all unqualified domain names. For example, if the default domain name is fourex.oz and the defname flag is enabled, a query for the name toolah automatically generates a query packet containing the domain name toolah.fourex.oz.
- A timeout error occurs if the name server is not running or is unreachable. A Non-existent Domain error occurs if any resource record type for the specified domain name is not available at the name server. A Server Failed error occurs when the local name server cannot communicate with the remote name server.
- NSLOOKUP might interpret typing or syntax errors in subcommands as queries. This results in a query being sent and the name server response printed. The response is usually Non-existent Domain, which indicates that the server could not find a match for the query.