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DCMT VARY TCP/IP Parameters

broadcast-parms

Specifies to execute the DCMT command on all or a list of data sharing group members.

Note: For more information about broadcasting and broadcast-parms, see How to Broadcast System Tasks in the System Tasks and Operator Commands Guide.

STAtus

Switches the status of the TCP/IP support ON or OFF in the DC/UCF system.

ON KEEp

Enables or reenables TCP/IP support in the DC/UCF system. If reenabling TCP/IP support in the system, the latest value of each option is kept.

ON RESet

Enables or reenables TCP/IP support in the DC/UCF system. If reenabling TCP/IP support in the system, the value of each option is set to its original value.

OFF QUIesce

Prevents the creation of any new sockets, but allows executing applications using sockets to finish processing. All the LISTENER and DDSTCPIP PTERM's are closed. QUIesce is the default option for a DCMT VARY TCP/IP STATUS OFF command. By default, the QUIesce command waits indefinitely until all the socket descriptors are closed.

WAIt wait-time Sets a maximum time interval the QUIesce command should wait for all socket descriptors to close. wait-time is a positive number between 1 and 32767. When this time interval is exhausted or when the quiesce request is canceled, the following occurs, depending on the KEEp or FORce option specified on the WAIt clause:

  • If KEEp is specified (default value), TCP/IP is reenabled in the same way as using a DCMT VARY TCP/IP STATUS ON KEEP command.
  • If FORCe is specified, TCP/IP is disabled in the same way as using a DCMT VARY TCP/IP STATUS OFF FORCE command.
OFF FORce

Immediately terminates TCP/IP support in the DC/UCF system. All the LISTENER and DDSTCPIP PTERM's are closed, including all active sockets. Applications using sockets receive an error code on their next socket function call.

CANcel

Cancels an outstanding DCMT VARY TCP/IP STATUS OFF QUIESCE command. The KEEp or FORCe option overwrites the KEEp or FORCe option specified on the DCMT VARY TCP/IP STATUS OFF QUIESCE command.

TCP_NODelay

Switches the TCP_NODELAY socket global option ON or OFF.

DEFault STAck stack-name

Overwrites the default stack assigned by the system. Changing the default stack dynamically has no effect on the existing sockets. Only the newly created sockets that use the default stack affinity are affected. This option is useful only in a multiple stack environment.

INClude STAck stack-name

Includes (activates) a TCP/IP stack in the DC/UCF system. stack-name is the job name of a TCP/IP stack and is limited to eight characters. This option is used differently depending on the operating system:

EXClude STAck stack-name

Excludes a TCP/IP stack that is included (active) in the DC/UCF system. stack-name is the job name of a TCP/IP stack. The stack-name is limited to eight characters.

MAXimum SOCkets max-socket

Specifies the maximum number of sockets that can be created globally in the DC/UCF system. max-socket is a positive number between 1 and 65535. The maximum number of sockets that can be created in one address space can also be limited by the operating system, for example, through USS definitions under z/OS.

MAXimum SOCkets PER TASk max-socket-per-task

Specifies the maximum number of sockets that can be created by a single task in the DC/UCF system. The maximum value and the default value for this parameter are both equal to the value assigned at runtime to max-socket. If the max- socket-per-task value is greater than max-socket, it is truncated.

SERvices FILe REFresh

Refreshes the internal copy of the services file in memory after the services file has been updated.

Note: To make updates to the services file while the data set is currently defined in the startup JCL with the DISP=SHR option, the file should be allocated as a member from a PDS.

SERvices FILe CASe

Changes the case sensitivity that applies to the services names specified on the GETSERVBYNAME function calls.

STACk TABle REFresh

(z/OS only) Refreshes the list of stacks currently defined to CINET without the need to stop the TCP/IP support in the DC/UCF system. This command is accepted only when the TCP/IP status is ON.

If a new stack has been added to the list, it will not be activated in the DC/UCF system automatically. You must issue an explicit DCMT VARY TCP/IP INCLUDE STACK command to activate it in the DC/UCF system. The DCMT DISPLAY TCP/IP STACK TABLE shows the value New in the Active column from the corresponding entry.

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