The DFH0IPCC migration utility
The DFH0IPCC utility program that is provided with CICS® converts existing APPC and MRO connections to IPIC connections (IPCONNs). DFH0IPCC is a sample program for use with the DFHCSDUP system definition utility program. The utility generates a set of statements that form the input to DFHCSDUP.
The DFH0IPCC program takes input supplied in a table that you can edit, called an APPLID table. This table is used to store the APPLIDs of all the regions in the relevant setup, with the corresponding HOST name of the region and the listening PORT of the TCPIPSERVICE definition used to deal with inbound TCP/IP connections.
The DFH0IPCC program examines lists and resource groups in the CSD for CICS regions, collecting information about the CONNECTION and SESSIONS definitions it finds. For each APPC or MRO pair of CONNECTION and SESSIONS definitions, it creates an IPCONN definition. Where appropriate, the attributes of the IPCONN definition are taken from the CONNECTION and SESSIONS definitions, with the values of the remaining attributes taken from the APPLID table or allowed to take their default values. When the utility program has completed an IPCONN definition, it writes a series of DEFINE statements, which form the SYSIN for your resulting DFHCSDUP invocation JCL.
IPCONN attribute mapping
| IPCONN definition attribute | Migrated From or Created By | Comments |
|---|---|---|
| APPLID | CONNECTION (NETNAME) | Direct migration |
| AUTOCONNECT | CONNECTION (AUTOCONNECT) | Direct migration. But, if ALL, set the new value to YES. |
| CERTIFICATE | N/A | Blank |
| CIPHERS | N/A | Blank |
| DESCRIPTION | N/A | Blank. Not migrated. You can add this in the DFH0IPCC output. |
| GROUP | CONNECTION (GROUP) SESSIONS (GROUP) | Not changed |
| HOST | APPLID table | Must be specified in the APPLID table. |
| INSERVICE | CONNECTION (INSERVICE) | Direct migration |
| IPCONN | CONNECTION (CONNECTION) | Direct migration. See IPCONN names. |
| MAXQTIME | CONNECTION (MAXQTIME) | Direct migration |
| NETWORKID | APPLID table | No equivalent. Leave blank if not specified in the APPLID table or if using the default. |
| PORT | APPLID table | Must be specified in the APPLID table. |
| QUEUELIMIT | CONNECTION (QUEUELIMIT) | Direct migration |
| RECEIVECOUNT | Sum of SESSIONS (MAXIMUM) | Direct migration from the MRO SESSIONS equivalent setting, or derived from the APPC SESSIONS MAXIMUM setting. |
| SECURITYNAME | CONNECTION (SECURITYNAME) | Direct migration from CONNECTION SECURITYNAME only. |
| SENDCOUNT | Sum of SESSIONS (MAXIMUM) | Direct migration from the MRO SESSIONS equivalent setting, or derived from the APPC SESSIONS MAXIMUM setting. |
| SSL | N/A | Left blank. You can modify this in the DFH0IPCC output. |
| TCPIPSERVICE | APPLID table | Always “DFHIPIC” or as in the APPLID table. See TCPIPSERVICE names. |
| USERAUTH | CONNECTION (ATTACHSEC) | Direct migration from CONNECTION ATTACHSEC values LOCAL, IDENTIFY or VERIFY only. |
| XLNACTION | CONNECTION (XLNACTION) | Direct migration |
IPCONN names
The IPCONN names are generated to avoid duplicates. The DFH0IPCC utility program uses the name of the CONNECTION definition because there is a one-to-one relationship between a CONNECTION definition and the IPCONN definition created from it. The coexistence of same-name CONNECTION and IPCONN definitions is fully supported by CICS provided that the CONNECTION NETNAME and IPCONN APPLID are the same. In this instance, CICS selects the IPCONN definition instead of the CONNECTION definition for routing of supported function.
TCPIPSERVICE names
Because an IPCONN definition cannot determine the TCPIPSERVICE name of a partner region, the utility cannot produce TCPIPSERVICE definitions; you must define them manually. The utility works in such a way that all TCPIPSERVICE names in regions for which the utility produces IPCONN definitions must be the same.
All IPCONN definitions created by the DFH0IPCC utility program have the default attribute, TCPIPSERVICE (DFHIPIC), unless you supply a different name using the .DEFAULT row in the APPLID file. If you specify another name, use that name for all TCPIPSERVICE definitions that you create.