CICS® supports virtual hosting through the URIMAP resource definition object.
Each URIMAP definition that you set up for CICS as an HTTP server (with USAGE(SERVER) in the URIMAP definition), includes the host name that the Web client is expected to supply in its request. CICS automatically creates virtual hosts for you, by grouping together into a single data structure all the URIMAP definitions in a CICS region that specify the same host name and the same TCPIPSERVICE definition. URIMAP definitions that specify no TCPIPSERVICE definition, and therefore apply to all of them, are added to all the data structures that specify a matching host name, so these URIMAP definitions might be part of more than one data structure. Each of these groups of URIMAP definitions then forms a virtual host that can be managed as a single unit.
CICS automatically deletes virtual hosts if all the URIMAP definitions that made up the virtual host have been deleted. If you do not want to manage the virtual hosts that CICS has created for you, then you can ignore them, and manage at the level of your URIMAP definitions.
You can also process virtual hosts using an analyzer program. The host name for an HTTP request is passed to the analyzer program, and you can code the program to provide a host-dependent response to the request. However, virtual hosts that are set up in this way cannot be managed using the INQUIRE HOST, SET HOST and virtual host browsing commands.