The resolver address space must be started before any application or TCP/IP stack resolver calls can occur. When the address space starts, it reads an optional resolver setup data set that is pointed to by the SETUP DD card in the resolver JCL procedure. To use the functions that are provided by the GLOBALTCPIPDATA statement and other statements, you must define a resolver address space. You use a BPXPRMxx statement, RESOLVER_PROC, to specify the procedure name, if any, to be used by z/OS® UNIX to start the resolver address space. If the RESOLVER_PROC statement is not in the BPXPRMxx parmlib member or is specified with the procedure name DEFAULT, z/OS UNIX starts a resolver address space that has the assigned name RESOLVER.