Programs that query a name server are called resolvers. Because many TCP⁄IP applications need to query the name server, a set of routines is usually provided for application programmers to perform queries. However, utility programs with resolver interface are provided for system administrators to interactively query and update the name server.
The TSO DIG command uses the z/OS Communications Server provided resolver for resolver facilities. The BIND 9 onslookup and dig commands use the resolver initialization facilities of the z/OS Communications Server provided resolver but use their own resolver for additional resolver facilities needed. For a complete discussion of resolver configuration files, see the z/OS Communications Server: IP Configuration Guide.
Restriction: Scope information is not permitted on the operands that represent the target host name on the NSLOOKUP, onslookup, nslookup, nsupdate, DIG (TSO), or dig (z/OS UNIX) utility programs.