The TCP/IP protocols locate a system on a network by using its IP address. However, a host name enables you to identify systems more easily than IP addresses.
Many networks organize their hosts and routers into a hierarchy of administrative domains. If you are using the domain name system (DNS) or the Network Information Service (NIS) naming system, you must select a domain name for your organization that is unique worldwide. To ensure that your domain name is unique, you should register the domain name with InterNIC. A unique domain name is required if you plan to allow other sites on the Internet locate your systems through DNS.
The domain name structure is hierarchical. A new domain typically is located under an existing, related domain. For example, the domain name for a subsidiary company can be located below the domain of the parent company. If the domain name has no other relationship, an organization can place its domain name directly under one of the existing top-level domains such as .com, .org, .edu, .gov, and so forth.
In Oracle Solaris, you can select from three types of naming services: local files, NIS, and DNS. Naming services maintain critical information about the machines on a network, such as the host names, IP addresses, and so forth. You can also use the LDAP directory service in addition to or instead of a naming service. LDAP is a secure network protocol that is used to access directory servers for distributed naming and other directory services. This standard based protocol supports a hierarchical database structure. The same protocol can be used to provide naming services in both UNIX and multi-platform environments. For an introduction to naming services in Oracle Solaris, refer to Chapter 1, About Naming and Directory Services in Working With Oracle Solaris 11.4 Directory and Naming Services: DNS and NIS.
The configuration of the network databases is critical. Therefore, you need to decide which naming or directory service to use as part of the network planning process. Moreover, the decision to use naming services also affects whether you organize your network into an administrative domain.
For a naming or directory service, you can select from the following choices:
DNS – The DNS naming service maintains network databases on several servers on the network. See Working With Oracle Solaris 11.4 Directory and Naming Services: DNS and NIS for a description of these naming services and information about how to configure the databases. In addition, the guide explains the namespace and administrative domain concepts in more detail.
LDAP – You can also use the LDAP directory service in addition to or instead of a naming service. LDAP is a secure network protocol that is used to access directory servers for distributed naming and other directory services. For more information, see Working With Oracle Solaris 11.4 Directory and Naming Services: LDAP.
Local files – If you do not implement NIS, DNS, or LDAP, the network uses local files to provide the naming service. The term "local files" refers to the series of files in the /etc directory that the network databases use. The procedures in this book assume you are using local files for your naming service, unless otherwise indicated.
NIS – The NIS naming service is supported in this release. See Working With Oracle Solaris 11.4 Directory and Naming Services: DNS and NIS.
Plan a naming scheme for the systems that will comprise the network. Each machine on the network should have a TCP/IP host name that corresponds to the IP address on its primary network interface. The host name must be unique within the sub-domain of the system. Just like physical machines, virtual systems should also have a unique IP address and host name.
The following system configurations are possible:
Multiple host names that map to the IP address of the system. For example, systema.example.com can also be known as www.example.com
The same host name for both IPv4 and IPv6 addresses
A new IP address and an old deprecated IP address that are configured with the same host name for a period of time to support network renumbering
Multiple network interfaces on different subnets, each with a unique IP address and host name
When planning your network, make a list of IP addresses and their associated host names for easy access during the setup process. The list can help you verify that all of your host names are unique.