7-2 Netra Internet Server 3.1 User’s Manual—September 1996
7
The Netra server can use any or all of the name services at the same time. If
you decide to use more than one name service, they are tried in the following
order: local name service, NIS, DNS. For example, suppose your Netra server
is configured to use the local name service and DNS. When a name service
query is made, the server attempts name resolution by looking up the host
name in the local database first. If the host name is found, the server returns
the host address. If not, the query is passed to the DNS server. If the DNS
server resolves the query, it returns the information, otherwise it returns “not
found”.
Local Name Service
The local name service provides a local database that associates the names of
hosts with their host addresses. This name service is only available to
programs running on the Netra server.
Network Information Service
The NIS name service provides information about the local network. This
information can include more than host names and addresses (such as users
and passwords). However, the Netra server can only use NIS for host names,
host aliases, and host addresses.
Domain Name Service
DNS gives different groups responsibility for subsets of names. Each subset or
level is called a domain. At the top level of the DNS hierarchy are a small
number of large domains, such as com (for commercial organizations).
Individual organizations set up their own domains within these domains
(sun.com, oracle.com, stanford.edu). Domains, in turn, can have
subdomains. Domain names are requested from and registered by the Network
Information Center (NIC) for an annual fee.
The host name of a system, together with its full domain specification, makes
up a complete DNS name. For example, Figure 7-1 shows such a DNS name:
ren.comedy.tv.net. The machine ren is a node residing in the subdomain
comedy within in the domain tv, which is the domain net.
To Next Page
Loading...
