TCP/IP Considerations

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A network map entry is not required for every TCP/IP node. A default entry provides a standard set of parameters. If the standard set of parameters is not adequate, you can code a network map entry for that node to override the default entry. If network map entries are not used for TCP/IP, you must submit Processes by using the SNODE=TCPNAME keyword. For more information, see Example - Defining a TCP/IP Default Entry.

Note: If you set the NETMAP.CHECK=TCP initialization parameter, you must define the TCP/IP node in the local network map.

The APPLIDS and LOGMODE keywords and the remote library name positional parameter are not used on any TCP/IP node and cannot be coded in the network map. A warning is generated for any unnecessary keyword or subparameter, and the coded value is ignored when the network map is loaded.

Starting from the 6.4 release, IBM Connect:Direct z/OS generates a statistical report whenever a NETMAP error SVTR017I or SVTR009I occurs on the SNODE side. This report will trigger the Connection Started event in IBM Sterling Control Center.

TCP/IP Addressing

Each host on a TCP/IP network is assigned a unique address known as an IP address. Applications running on a TCP/IP host that connect to the network are assigned one or more port numbers of the IP address.

IBM® Connect:Direct® supports both IPv4 and IPv6 protocols, where IPv6 allows a much larger address range than IPv4. During product initialization, IBM Connect:Direct determines if the TCP Stack is IPv6 or only IPv4. (IPv6 must be enabled within TCP/IP itself.) If IBM Connect:Direct initializes on a system where IPv6 is not enabled, any function involving an IPv6 address fails, including attempts to resolve an address or name using the DNS name resolution. For information about enhancing and extending IPv6 through the TCP.LISTEN parameter, see Multiple Port TCP/IP Listen.

Command Syntax for IPv4 AND IPv6 Addressing

The following examples demonstrate the command syntax for IPv4 and IPv6 addressing.

Note: The address must be specified on a single line. You cannot break the address between lines.

The following example demonstrates how to break the command syntax over an additional line:

(SC.DUB.MWATL3,4399,   -
1111:2222:3333:4444:5555:6666:7777:8888,TCP)

The following example demonstrates the appropriate network syntax:

/*                */
/*  IPV6 ADDRESS  */
/*                */
   ADJACENT.NODE=(    -
     (SC.DUB.MWATL3,4399,1111:2222:3333:4444:5555:6666:7777:8888,TCP) -
     PARSESS=(00000255 00000001) -
     APPLIDS=(M1CDI7P6 M1CDI7P7 M1CDI7P8) )
/*                */
/*  IPV4 ADDRESS  */
/*                */
   ADJACENT.NODE=(    -
     (SC.DUB.MWATL3,4399,111.222.333.444,TCP) -
     PARSESS=(00000255 00000001) -
     APPLIDS=(M1CDI7P6 M1CDI7P7 M1CDI7P8) )

The following example demonstrates the appropriate command syntax for a multiple listen for IPv6 addresses through the initialization parameter:

TCP.LISTEN=((10.20.201.2,4199),  -
            (fd00:0:0:20cc::2,4299),  -
            (10.20.201.2,4399),  -
            (10.20.201.2,4499) )

The following two examples represent a simple specification for a single listen for either an IPv4 or IPv6 address through the initialization parameters:

/*                 */
/*  IPV4 address   */
/*                 */
    TCP.LISTEN = (111.222.333.444,01364)

/*                 */
/*  IPV6 address   */
/*                 */
    TCP.LISTEN = (1111:2222:3333:4444:5555:6666:7777:8888,01364)

The following example represents a simple specification for a single listen for either an IPv4 or IPv6 address through the Process syntax:

/*                 */
/*  IPV6 Address   */
/*                 */
label PROCESS   -
  SNODE=TCPNAME=1111:2222:3333:4444:5555:6666:7777:8888;nnnnn
/*                 */
/*  IPV4 Address   */
/*                 */
label PROCESS SNODE=TCPNAME=111.222.333.444;nnnnn
(where nnnnn is the 5 digit port number)

Domain Name Resolution

Because IP addresses are difficult to remember and not descriptive of the host it is assigned to, TCP/IP enables meaningful names to map to the IP address. TCP/IP provides a function called Domain Name Resolution to map the name to the IP address. Refer to your TCP/IP implementation documentation for information on the setup and use of Domain Name Resolution.

Releasing Processes Serially from Connect:Direct for Microsoft Windows

To support dial-up connections from a Connect:Direct for Microsoft Windows node and release Processes serially, define the Connect:Direct for Microsoft Windows node in an adjacent node entry using a null IP address of 0.0.0.0. You can let the port number default to 1364 on the node where the network map resides since it will be resolved at connection time. Processes submitted to nodes defined in this manner default to HOLD=CALL status and are not executed since the connection cannot be resolved.

To release the HOLD=CALL Processes, create a NULL or ENABLE Process from the Connect:Direct for Microsoft Windows SNODE. (A NULL Process is an empty one with no steps and is only valid in Connect:Direct for Microsoft Windows.) When the Connect:Direct for Microsoft Windows node establishes a connection with IBM Connect:Direct for z/OS® and sends the NULL Process, IBM Connect:Direct for z/OS uses the same session and runs any HOLD=CALL Processes one at a time. Checkpoint restart is supported for such nodes.