What is required to institute a change to the ENF control option, CICSREL, when a new CICS release is introduced. Can it be updated dynamically?
CAIENF/CICS Intercept modules are loaded into CSA or ECSA at CAIENF startup, and reside there until the next IPL. Therefore you must cycle ENF to bring in the new/added release of CICS (via the ENFPARM, CICSREL)
The 'HOOKS' loaded into CSA do not 'UNHOOK' when bringing down ENF. So, the ENFCICS INTERFACE (SECURING YOUR CICS REGIONS) will not get 'UNHOOKED'.
Steps to properly install and interface:
Another option is to load the intercept in CICS private. This is explained in the documentation -
How CAIENF/CICS checks for Intercept Modules
Configure CAIENF/CICS to Install Intercepts Automatically in Specific CICS Regions
If you needed to apply maintenance to pickup support for newer release, then you will need to pass the REINIT option on the restart of ENF. The proper syntax is: S ENF,,,REINIT.
ENF must reference any updated modules from either a STEPLIB or the system LNKLIST. If loading from the system LNKLIST be sure to refresh LLA prior to recycling the ENF address space.