The TCPIP.DATA data set is the only one of the TCP/IP data sets for which a unique copy is needed for each transport provider. This is because the TCPIPJOBNAME statement identifies the TCP/IP address space and the HOSTNAME statement identifies the host name of the TCP/IP address space.

Datasetprefix         TCPIP.TEST1     ; This stack's data set prefix
TCPIPjobname          TCPCO1          ; Stack name
NSinterAddr           127.0.0.1       ; Name server (on this system)
NSportAddr            53              ; Name server port number
ResolveVia            UDP             ; Use UDP for Name server
ResolverTimeout       30              ; 30-second name server timeout;
ResolverUdpRetries    1               ; Retry name server once
HostName              TCPIP1          ; My host name
DomainOrigin          pok.ibm.com     ; My domain origin
Messagecase           mixed           ; Issue mixed-case messages

domain pok.ibm.com
nameserver 9.114.75.254
nameserver 9.114.171.254
nameserver 9.114.151.254

The system processes this information during the initial request for service. It accepts either format for the information supplied regardless of the source selected.

When they are mixed, only the last domain or DOMAINORIGIN data is used and up to 16 name server's addresses are used for initialization. However, if you set up /etc/resolv.conf to supply resolver information, you must specify the DATASETPREFIX information in /etc/resolv.conf unless you have also set up /etc/services, /etc/protocol, and /etc/hosts files.

Any mix of MVS™ data sets and z/OS UNIX files can be used. For example, you could use the TCPIP.DATA information from SYS1.TCPPARMS, the service and protocol information from ETC.SERVICE and ETC.PROTO and use the /etc directory in the z/OS UNIX file system to record hosts names and addresses of the z/OS UNIX hosts file.