Steps for defining the resolver address space

You must define the resolver address space to use the functions provided by the GLOBALTCPIPDATA statement and other statements.

Perform the following steps to define the resolver address space:

1. Create a start procedure. The start procedure has the following requirements:
   • The procedure must not contain any DD cards that specify SYSOUT=*.
   • The procedure must be in a data set that is specified by the IEFPDSI DD card specification of the MSTJCLxx PARMLIB member. If the procedure is not in this location, the resolver will not start. For information about MSTJCL, see z/OS MVS Initialization and Tuning Reference.

   To process its definitions, the resolver might need to allocate data sets or files. For those definitions, such as GLOBALTCPIPDATA, DEFAULTTCPIPDATA, /etc/hosts, HOSTS.SITEINFO, and HOSTS.ADDRINFO, allocation messages appear in the JES joblog. For long-running applications that heavily use resolver services, such as IBM® Tivoli® NetView® for z/OS®, consider using a started job that specifies MSGLEVEL=(1,0) to eliminate all allocation messages. This specification could also eliminate allocation messages that might be useful for problem analysis. For information about started jobs and the MSGLEVEL parameter, see z/OS MVS JCL Reference.

   See the example resolver startup procedure.

2. In the SETUP DD JCL statement, specify the location of the setup file.
3. Grant read access (using RACF® or other security program) to the following files for the user ID that is assigned to the resolver address space:
   • SYS1.PARMLIB
   • The resolver setup file
   • The file specified by the GLOBALTCPIPDATA statement, if you are using one
   • The file specified by the DEFAULTTCPIPDATA statement, if you are using one
   • The file specified by the GLOBALIPNODES statement, if you are using one
   • The file specified by the DEFAULTIPNODES statement, if you are using one
4. If you are using any of the following files, grant read access to the files for the user IDs or jobs that are using TCP/IP facilities:
   • The file specified by the GLOBALTCPIPDATA statement
   • The file specified by the DEFAULTTCPIPDATA statement
   • The file specified by the GLOBALIPNODES statement
   • The file specified by the DEFAULTIPNODES statement
   • /etc/hosts
   • /etc/ipnodes
   • /etc/services
   • HOSTS.SITEINFO
   • HOSTS.ADDRINFO
   • ETC.IPNODES

   If you do not specify the correct permission bit settings for a file to allow that file to be read, error message IEC141I 013-C0 is issued. Other error messages might also be issued that indicate that a file cannot be read.

5. (Optional) If you want z/OS UNIX to start the resolver (rather than using automation to start the resolver with the MVS™ START operator command), specify the resolver start procedure name as the procname value in the RESOLVER_PROC(procname) statement of the BPXPRMxx parmlib member. See Starting the resolver for information about starting the resolver.
   Guideline: The default procedure name is RESOLVER. If you want to specify a procedure that uses the name RESOLVER, then specify RESOLVER for the procname value.

   If you do not specify the RESOLVER_PROC statement or if you specify DEFAULT, then z/OS UNIX starts a resolver address space using the system default procedure IEESYSAS with the assigned name RESOLVER. If you do not want to use z/OS UNIX to start the resolver, you must use the MVS START command to start the resolver address space.

6. If you use automation to start the resolver, consider looking for message EZD2038I and taking corrective action based on the warning messages that are generated by the resolver. The resolver issues messages during resolver address space initialization identifying the errors that exist in the resolver setup file. If the resolver issues message EZD2038I at the end of resolver address space initialization, there were setup statements with syntax errors or setup statements that were not recognized in the setup file. The errors might include errors accessing or opening one or more of the files specified on resolver setup statements, such as the GLOBALTCPIPDATA statement.

//RESOLVER PROC PARMS='CTRACE(CTIRES00)'
//*
//*   IBM Communications Server for z/OS
//*   SMP/E distribution name: EZBREPRC
//*
//*   5694-A01 Copyright IBM Corp. 2001, 2010.
//*   Licensed Materials - Property of IBM
//*
//*   Function: Start Resolver
//*
//EZBREINI EXEC PGM=EZBREINI,REGION=0M,TIME=1440,PARM=&PARMS
//*
//*   When the Resolver is started by UNIX System Services it is
//*     started with SUB=MSTR.
//*   This means that JES services are not available to the Resolver
//*     address space. Therefore, no DD cards with SYSOUT can be used.
//*     See the MVS JCL Reference manual for SUB=MSTR considerations in
//*     section "Running a Started Task Under the Master Subsystem".
//*   This Resolver start procedure will need to reside in a data
//*     set that is specified by the MSTJCLxx PARMLIB member's
//*     IEFPDSI DD card specification. If not, the procedure will
//*     not be found and the Resolver will not start.
//*     See the MVS Initialization and Tuning Reference manual for
//*     MSTJCL considerations in section "Understanding the Master
//*     Scheduler Job Control Language"
//*
//*   SETUP contains Resolver setup parameters.
//*     See the chapter "The resolver" in the
//*     IP Configuration Guide for more information. A sample of
//*     Resolver setup parameters is included in member RESSETUP
//*     of the SEZAINST data set.
//*
//*SETUP   DD   DSN=TCPIP.TCPPARMS(SETUPRES),DISP=SHR,FREE=CLOSE
//*SETUP   DD   DSN=TCPIP.SETUP.RESOLVER,DISP=SHR,FREE=CLOSE
//*SETUP   DD   PATH='/etc/setup.resolver',PATHOPTS=(ORDONLY)