>>-+---------------------------------------+------------------->< '-HOSTNAME--=--fully_qualified_hostname-'
Specifies the default host name associated with the local TCP/IP stack to be used for Enterprise Extender connections involving this node. The HOSTNAME you code should be a fully qualified TCP/IP domain name.
Recommendation: The value of hostname can be resolved to either an IPv4 address or an IPv6 address, but it is highly recommended that hostname resolve to a single VIPA address.
If the local TCP/IP stack has multiple static IPv4 VIPAs, use the value of hostname to optionally provide a host name for remote Enterprise Extender nodes to perform name-to-address resolution to acquire the appropriate static VIPA, or NAT address, to use in order to communicate with this host. The value of hostname will also be resolved by this node to acquire the static IPv4 VIPA to use for Enterprise Extender connections. The value of the IPADDR start option, or the first VIPA defined to the TCP/IP stack identified by TCPNAME, may be used as alternatives for identifying the default IPv4 static VIPA address for Enterprise Extender purposes.
You can specify a node-wide value for HOSTNAME to use IPv6 protocols for some or all of your EE connections. The value of hostname will be used by this node to perform name-to-address resolution in order to determine the appropriate static IPv6 VIPA for use with Enterprise Extender connections. Remote Enterprise Extender nodes wanting to communicate with this node will also perform name-to-address resolution using hostname to acquire the appropriate static VIPA required to ultimately reach this node. If the local TCP/IP stack has multiple static IPv6 VIPAs, use the value of hostname to indicate the appropriate static VIPA to use in order to communicate with this host. Alternatively, you can use the value of the IPADDR start option to identify the default IPv6 static VIPA address for EE connections.
- Your Enterprise Extender configuration uses both IPv4 and IPv6 addressing protocols.
- Your Enterprise Extender configuration uses multiple static VIPAs.
- The fully_qualified_hostname may be up to 64 characters in length. See z/OS Communications Server: SNA Network Implementation Guide for more information about HOSTNAME length considerations.
- The HOSTNAME start option is used only when the XCA major node PORT definition statement is coded as MEDIUM=HPRIP, and neither the HOSTNAME nor IPADDR operand is coded on the GROUP definition statement.
- HOSTNAME and IPADDR cannot be modified using one MODIFY VTAMOPTS command. If both start options are specified on the same MODIFY command, they will both be ignored and message IST1917I will be generated.
- The HOSTNAME start option can be dynamically modified using MODIFY
VTAMOPTS under certain conditions. An attempt to modify HOSTNAME to
be a fully qualified hostname will be failed
with message IST448I if a static VIPA address has been obtained from
the TCP/IP stack named in the TCPNAME start option and is being used
for active Enterprise Extender connections. All active Enterprise
Extender lines must be deactivated before the MODIFY VTAMOPTS,HOSTNAME=fully
qualified hostname will be accepted.
If the MODIFY command is successful, displays of VTAM® start options will show the new value immediately; however, the new value will not be used until all Enterprise Extender lines whose GROUP definition statements do not have HOSTNAME or IPADDR explicitly coded are inactive. Any subsequent activation for an Enterprise Extender line whose GROUP definition statement does not have HOSTNAME or IPADDR explicitly coded will make use of the new HOSTNAME start option value. If the IPADDR start option is currently in use when the MODIFY VTAMOPTS is performed to activate HOSTNAME, the IPADDR start option is set to 0.0.0.0 as part of processing the MODIFY VTAMOPTS.
The value of NONE can be specified for the HOSTNAME value on the MODIFY VTAMOPTS command as a mechanism for clearing the value of the current HOSTNAME start option. This option will fail, however, with message IST448I, if the Enterprise Extender XCA major node is active.
Enterprise Extender major node GROUP definition statements that have HOSTNAME or IPADDR explicitly coded are unaffected by setting the HOSTNAME start option, and are unaffected by the MODIFY VTAMOPTS processing.
- If neither the HOSTNAME nor IPADDR operand is specified on any of the GROUP definition statements within the Enterprise Extender XCA major node, then either the HOSTNAME, TCPNAME or IPADDR start option must be specified in order to initiate an Enterprise Extender link. If VTAM has been activated without the specification of one of these options, then the MODIFY VTAMOPTS command can be used to set one of these options. If an Enterprise Extender link activation is attempted without HOSTNAME, TCPNAME or IPADDR specified, then the link activation will fail with the IST1890I message.
- If HOSTNAME or IPADDR is specified on any GROUP definition statement within the Enterprise Extender (XCA) definition, it must be specified on all Enterprise Extender GROUP definition statements (or defaulted from the VTAM start options).
- The TCPNAME start option is required in a CINET environment if
any of the following conditions exist:
- The IPADDR parameter is specified on any of the Enterprise Extender XCA major node GROUP definition statements.
- The HOSTNAME parameter is specified on any of the Enterprise Extender XCA major node GROUP definition statements.
- The HOSTNAME keyword is specified as a VTAM start option.
If OMVS is not initialized at Enterprise Extender line activation, a Common INET environment is assumed.
In this case, if an Enterprise Extender link activation is attempted without TCPNAME specified, then the link activation will fail with message IST1897I.
- If both the IPADDR and the HOSTNAME start options are specified on the VTAM START command, the value of the IPADDR start option is ignored.
- HOSTNAME is meaningful only if the NODETYPE start option is also used.
- See z/OS Communications Server: IP Configuration Guide for information about UNIX Systems Services security considerations and required security definitions.