PATH definition statement

Code a PATH definition statement to define a path to a physical unit in a switched major node. You can code up to 256 PATH definition statements for each physical unit. The PATH definition statement must immediately follow the PU definition statement that defines the associated physical unit. VTAM® searches the PATH definition statements for an available path in the order given in the configuration deck.

Use the DWACT operand to enable automatic dialing of the PU when it is activated by specifying DWACT=YES. Enable the PU to be redialed automatically in the event of a dial failure by use of the REDIAL and REDDELAY operands. If you also would like redial to be attempted (using the REDIAL and REDDELAY specifications) in the event of a connection INOP, specify DWINOP=YES. See Switched major node operand descriptions for details.

The IPADDR keyword specifies the remote IP address for a dial-out connection. If the remote APPN node is a z/OS® Communications Server node, the address must be the VIPA address the remote node is currently using for the Enterprise Extender connections. For example, the VIPA address specified or defaulted to on the IPADDR VTAM start option or modified by the F VTAMOPTS, IPADDR operator command.

The HOSTNAME keyword specifies the name of the remote (destination) host name for a dial-out connection. IPADDR and HOSTNAME keywords are mutually exclusive. Use of this keyword implies that the local z/OS CS node can perform TCP/IP name-to-address resolution, either by connectivity to a DNS name server, or by using a local hosts file such as HOSTS.SITEINFO or /etc/ipnodes. If the host name is specified and cannot be resolved, the dial will fail. For more information, see z/OS Communications Server: IP Configuration Guide. The DNS name servers and local hosts files must be configured to only return VIPA addresses if the name represents a z/OS CS APPN node, and the VIPA address returned must be one that is usable for Enterprise Extender connections on the remote VTAM node. For information about displaying information on networks and hosts, see z/OS Communications Server: IP User's Guide and Commands.

In order to use HOSTNAME, VTAM will use the system-wide resolver function. If you intend for the resolver to use a name server to resolve HOSTNAME, the resolver will use the TCPIP.DATA file to determine the IP addresses of name server(s) to use. TCPIP.DATA also contains other necessary information such as the local domain name, local host name, and so on. If you intend to use a local hosts file instead of a name server, there is a specific search order used to find the correct data set. See z/OS Communications Server: IP Configuration Guide for information on the search order for local hosts files.

In order to use HOSTNAME, VTAM must be able to find one or more TCPIP definition files. This is done by way of the Native MVS™ Sockets resolver. Do not confuse this with the LE Resolver, sometimes referred to as the z/OS Resolver. If you intend to use a name server to resolve HOSTNAME, VTAM must be able to find the TCPIP.DATA file, which in turn, contains the IP addresses of name servers to use. It also contains other necessary information such as the local domain name, local host name, etc. If you intend to use a local HOST table instead of a name server, there also is a specific search order to find this data set. See z/OS Communications Server: IP Configuration Guide for information on the search order for Local Hosts tables.

Note: These data sets cannot be concatenated like many MVS data sets can.

The SAPADDR keyword specifies the remote service access point (RSAP) value.

For predefined Enterprise Extender connections, coding a PATH definition statement with GRPNM allows an incoming call to prefer one switched PU over another. When the GROUP name, associated with the line selected for the inbound call, matches the GRPNM on the switched PATH, the switched PU associated with the PATH is preferred over another switched PU that does not match, or does not have a PATH definition statement coded.

Note: The GRPNM keyword ties the switched major node PATH statement to the XCA major node. The name on the XCA GROUP statement must match the value on the GRPNM in the SMN PATH.