To use TCP/IP in a CICS® region, you must provide the following:
You can change the resolver configuration of CICS either by altering system TCP/IP configuration files, or by adding or changing the DD name SYSTCPD in the CICS start-up JCL. This sets the RESOLVER_CONFIG environment variable to the MVS dataset you have specified. This file is described in the z/OS IBM® Communications Server: IP Configuration Guide, SC31-8775. It contains a reference to the DNS server's IP address.
You must specify at least the following:
where n.n.n.n is the dotted decimal address of the name server to be used.
If the DD name is not included in the startup JCL, a number of system files are searched until one is found.