IPv4-unique search order for sitename information

The resolver uses the IPv4-unique search order for sitename information when the resolver setup statement NOCOMMONSEARCH is specified (or left to default), and either the:

• getaddrinfo API is attempting to locate an IPv4 address.
• gethostbyname, GetHostNumber, GetHostResol, IsLocalHost, Resolve, sethostent, gethostent, or endhostent API is invoked.

If the COMMONSEARCH statement is specified, see IPv6/common search order, where the resolver can use IPNODES to locate sitenames.

The resolver uses the IPv4-unique search order for sitename information unconditionally for getnetbyname API calls.

The IPv4-unique search order for sitename information is as follows. The search ends at the first file found:

1. userid/jobname.HOSTS.SITEINFO

   userid is the user ID that is associated with the current security environment (address space or task/thread).

   jobname is the name specified on the JOB JCL statement for batch jobs or the procedure name for a started procedure.

2. hlq.HOSTS.SITEINFO

   hlq represents the value of the DATASETPREFIX statement specified in the base resolver configuration file (if found); otherwise, hlq is TCPIP by default.