OPTIONS statement

Use the OPTIONS statement to specify:

Whether or not resolver debug messages should be issued
The number of periods (.) that need to be contained in a domain name for it to be considered a fully qualified domain name

Guideline: The NDOTS and DEBUG options are independent; setting one of them does not imply a setting for the other.

Syntax


                              .-------------.   
                              V             |   
>>-+--------------+--OPTIONS----+---------+-+------------------><
   '-system-name:-'             +-DEBUG---+     
                                '-NDOTS:n-'

Parameters

system_name:

The name of the system to which this statement applies. See system_name considerations for a complete description of this parameter.

Requirement: The colon is required.

DEBUG

Specifying DEBUG is equivalent to the Trace Resolver statement. Debugging messages from the resolver are generated.

If OPTIONS DEBUG is anywhere in the TCPIP.DATA file, then tracing is on. It should be the first statement in the TCPIP.DATA statements to get the maximum trace output. The initial default setting is for no debug messages to be specified. Do not specify OPTIONS DEBUG in the GLOBALTCPIPDATA file.

NDOTS:n

Specifies that for a domain name that contains n or more periods (.), the resolver should try to look up the name as is before applying the DOMAINORIGIN or SEARCH statement settings.

Requirement: The colon is required.

A maximum of 15 is allowed for n. Any value for n not in the range 1 - 15 results in n being set to 1. Not specifying the NDOTS:n parameter results in the current setting remaining in effect (if no value has yet been specified on any previous OPTIONS statements, then NDOTS:1 is the setting).

Use care when setting n greater than 1. For example, consider the following:

If NDOTS:2 was specified and the DOMAINORIGIN statement had mit.edu specified, the following results would be observed:
- A user enters ftp prep.ai. Resolution of domain name prep.ai.mit.edu would be tried. If that fails resolution, then the name prep.ai would be tried.
- A user enters ftp prep.ai.mit. The domain name prep.ai.mit would try to be resolved. If that fails resolution, then the name prep.ai.mit.mit.edu would be tried.
- A user enters ftp prep. The domain name prep.mit.edu would try to be resolved. If that fails resolution, then the name prep would be tried.
If NDOTS:1 was specified and the SEARCH statement had ai.mit.edu and MIT.EDU specified, the following results would be observed:
- A user enters ftp prep.ai. The domain name prep.ai would try to be resolved. If that fails resolution, then the name prep.ai.ai.mit.edu would be tried. If that fails resolution, then the name prep.ai.MIT.EDU would be tried.
- A user enters ftp prep. The domain name prep.ai.mit.edu would try to be resolved. If that fails resolution, then the name prep.MIT.EDU would be tried. If that fails resolution, then the name prep would be tried.
If the name specified by the user ends with a period (.), then both the NDOTS:n specification and the DOMAINORIGIN or SEARCH values are ignored. For example, a user enters ftp prep.ai.. The domain name prep.ai. would try to be resolved. If that fails, no other name is tried.

Steps for modifying

You can refresh this statement using the MODIFY command. For more information about parameters used with the MODIFY command, see z/OS Communications Server: IP System Administrator's Commands.

Examples

The following statement sets NDOTS to 2 and also requests resolver debug messages:

OPTIONS NDOTS:2 DEBUG

The following statement requests resolver debug messages and by default set NDOTS to 1:

OPTIONS DEBUG

The following set of statements in a single TCPIP.DATA file sets NDOTS to 3 and also request resolver debug messages:

OPTIONS NDOTS:2 DEBUG
OPTIONS NDOTS:3

The following set of statements in a single TCPIP.DATA file would set NDOTS to 3 and also request resolver debug messages.

OPTIONS NDOTS:2
OPTIONS NDOTS:3 DEBUG
OPTIONS

Usage notes

If the OPTIONS statement is not specified or specified without a NDOTS:n parameter (for example, OPTIONS specified only with the DEBUG parameter), a value of :1 is assigned. Do not specify the OPTIONS DEBUG parameter in the GLOBALTCPIPDATA file.
Guideline: This assumes only one OPTIONS statement in the TCPIP.DATA file.
If multiple OPTIONS NDOTS:n statements are encountered in a single TCPIP.DATA file, the last statement takes effect.
If an OPTIONS statement without the DEBUG parameter is specified, the previous debug setting stays in effect. The default setting is for no debug messages to be specified.