VARY LOGON command


>>-VARY-- --NET--,--LOGON--=--appl_name--,--ID--=--slu_name----->

>--+--------------------------------+--+--------+--------------><
   '-,--LOGMODE--=--logon_mode_name-'  '-,--ACT-'

Abbreviations

Operand	Abbreviation
VARY	V

Purpose

You can use the VARY LOGON command to change an existing automatic logon specification or to create an automatic logon specification. This command applies to any device-type logical unit, whether channel-attached or link-attached. Neither the device-type logical unit, which is the secondary LU, nor the primary LU receiving the automatic logon has to be active when the VARY LOGON command is issued.

Note: This command is restricted to the VTAM® owning the SLU specified in the ID operand.

An automatic logon specification remains in effect until one of the following situations occurs:

The primary logical unit controlling the secondary logical unit is changed with VARY LOGON or VARY ACT,LOGON command.
A VARY NOLOGON command is entered for the secondary logical unit.

Note: If you use the VARY LOGON command to create or change an automatic logon specification, be aware that later use of a VARY ACT,UPDATE=ALL command for dynamic reconfiguration can undo the effects of the VARY LOGON command. This is because the LOGAPPL value in the definition file overrides the value that was established with the VARY LOGON command. Even if no LOGAPPL is coded in the definition file, VTAM assumes a null value for LOGAPPL and the null value overrides the VARY LOGON value. To prevent the automatic logon specification from being deleted unintentionally, code the LOGAPPL definition statement with the required value.

Any automatic logon request made as a result of this specification might be accepted or rejected by the primary LU.

The VARY LOGON command specifies only a primary LU session partner for automatic logon (when the specified secondary LU becomes available for a session); it does not activate the secondary LU. To activate the secondary LU (or a resource to which the secondary LU is subordinate) and change the automatic logon specification at the same time, use the VARY ACT command with the LOGON operand (see the LOGON operand on the VARY ACT command for more information).

For independent SLUs, the VARY LOGON command initiates a session with the controlling PLU only if there are no sessions already established with the specified PLU. Repeated use of the VARY LOGON command for the same LU and controlling PLU establishes only a single session. A series of VARY LOGON commands for the same LU specifying different controlling PLUs establishes sessions between the LU and each of the controlling PLUs specified. The controlling PLU is the one specified in the last command. The other sessions are not automatically re-established after they terminate.

Note: When you enable automatic logons to TSO (either by using the VARY LOGON command or by specifying LOGAPPL=TSO in a definition statement), a new logon attempt is made when the user session ends, even if it ends in error. This is because it is not the session with TSO that is failing. If a loop occurs, for example message IKT029I being issued repeatedly, you can break the automatic logon relationship by issuing a VARY NOLOGON command. If you have a user-written application in your network called TSO, then enabling automatic logons to TSO could have unpredictable results.

Operands

ACT

Activates any subordinate resources within the scope of this command. If ACT is specified on the VARY LOGON command, other operands of the VARY ACT command are available. See Figure 1 for the operands you can use. Use the LOGON column of that table to identify which resources are applicable.

ID=slu_name

Specifies the name of the secondary LU. This name can be one of the following values:

A device-type logical unit
A resource with subordinate device-type logical units
A boundary function CDRSC

If the value is a boundary function CDRSC, the boundary function CDRSC named must be known to VTAM at the time the command is issued. That is, it must have been predefined, cloned from a model CDRSC, or dynamically defined because of another session. In addition, it must have a default ALS list.

Boundary function CDRSCs are subordinate only to the CDRSC major node where they were defined (ISTPDILU or ISTCDRDY). Boundary function CDRSCS are not subordinate to any device type major node (NCP, local SNA, and so), nor to a line or PU, even if the independent LU was defined within or under these resources.

Because of this, independent LUs are not subordinate to any PU. Therefore, the sift-down to subordinate LUs does not affect independent LUs unless the ID value is a CDRSC major node.

The VARY LOGON command affects only LUs. If another resource type is specified, the logical units affected are those subordinate to the resource that is specified on this command.

The name can be a network-qualified name. If the name specified on the ID operand is network-qualified, this name is considered to be the real name of the resource.

If the ID operand specifies a model CDRSC, then future clone CDRSCs built using the model are affected by this operation. To affect an existing clone CDRSC, issue the VARY LOGON command against that clone CDRSC.

If the ID operand specifies a CDRSC major node, then all the CDRSCs in that major node are affected. That includes conventionally defined CDRSCs, model CDRSCs, and clone CDRSCs.

LOGMODE=logon_mode_name

Specifies the name of the logon mode entry to be used for any logon initiated for a logical unit as a result of this command. This logon mode name also becomes the logon mode name for all future automatic logons performed by VTAM for logical units within the scope of this command, and for their controlling primary LUs (if any).

LOGON can be specified without LOGMODE, but LOGMODE cannot be specified without LOGON. If LOGMODE is specified without the LOGON operand, LOGMODE is ignored and no error message is sent.

If LOGMODE is not specified, the LOGMODE value specified in any previous command applicable to a logical unit within the scope of this current VARY LOGON command is used. If no LOGMODE value was ever specified for a given logical unit within the scope of this command, the logical unit's default value is used.

LOGON=appl_name

Specifies the name of an application program (primary LU) to which any secondary LUs within the scope of this command are to be logged on. The application name can be network-qualified. If it is, the network identifier is considered to be real, but the resource name is considered to be generic (that is, the resource name can be either the real application name or a USERVAR name).

If the application name is an ACB name, and the ACB name matches the name on the APPL definition statement, then you can use a network-qualified ACB name.

If a USERVAR is found, VTAM resolves its name to the name of the VTAM application with which it is currently associated. If a USERVAR with this name is not found, VTAM searches for an application program with this name.

If the primary LU is an application program in this domain, the name must be that of an application program minor node within an active application program major node.

If the primary LU is a predefined CDRSC, the CDRSC must be active.

If the primary LU is a device-type LU, it must be attached to the same NCP as the secondary LU.