By default, the DHCPv4 client does not supply its own host name, because the client expects the DHCP server to supply the host name. The DHCPv4 server is configured to supply host names to DHCPv4 clients by default. When you use the DHCPv4 client and server together, these defaults work well. However, when you use the DHCPv4 client with some third-party DHCP servers, the client might not receive a host name from the server. If the DHCP client does not receive a host name through DHCP, the client system checks the value that is set in the config/nodename property in the svc:/system/identity:node service for a name to use as the host name. If the file is empty, the host name is set to unknown.
If the DHCP server supplies a name in the DHCP Hostname option, the client uses that host name, even if a different value is placed in the value that is set in the config/nodename property in the svc:/system/identity:node service. If you want the client to use a specific host name, you can enable the client to request that name. See the following procedure.
However, the DHCP server does not have to respect this request and many do not. They simply return a different name.