To run in local files mode, a system must have local copies of the TCP/IP configuration files. These files are described in TCP/IP Configuration Files. The system should have its own disk, though this recommendation is not strictly necessary.
Most servers should run in local files mode. This requirement includes the following servers:
Network configuration servers
NFS servers
Name servers that supply NIS, LDAP, or DNS services
Mail servers
Additionally, routers should run in local files mode.
Systems that function exclusively as print servers do not need to run in local files mode. Whether individual hosts should run in local files mode depends on the size of your network.
If you are running a very small network, the amount of work that is involved in maintaining these files on individual hosts is manageable. If your network serves hundreds of hosts, the task becomes difficult, even with the network divided into a number of administrative subdomains. Thus, for large networks, using local files mode is usually less efficient. However, because routers and servers must be self-sufficient, they should be configured in local files mode.
Network configuration servers are the servers that supply the TCP/IP configuration information to hosts that are configured in network client mode. These servers support three booting protocols:
RARP – Reverse Address Resolution Protocol (RARP) maps Ethernet addresses (48 bits) to IPv4 addresses (32 bits), which is the reverse of ARP. When you run RARP on a network configuration server, hosts that are running in network client mode obtain their IP addresses and TCP/IP configuration files from the server. The in.rarpd daemon enables RARP services. Refer to the in.rarpd(1M) man page for details.
TFTP – The Trivial File Transfer Protocol (TFTP) is an application that transfers files between remote systems. The in.tftpd daemon executes TFTP services, enabling file transfer between network configuration servers and their network clients. Refer to the in.tftpd(1M) man page for details.
Bootparams – The Bootparams protocol supplies parameters for booting that are required by clients that boot off the network. The rpc.bootparamd daemon executes these services. Refer to the bootparamd(1M) man page for details.
Network configuration servers can also function as NFS file servers.
If you are configuring any hosts as network clients, then you must also configure at least one system on your network as a network configuration server. If your network is subnetted, then you must have at least one network configuration server for each subnet with network clients.