Some network servers provide essential computer-to-computer services. These differ from application services in that they are not directly accessed by end users. Instead, these services are used by networked computers to simplify the installation, configuration, and operation of the network.
The functions performed by the servers covered in this chapter are varied:
Name service for converting IP addresses to hostnames
Configuration servers that simplify the installation of networked hosts by handling part or all of the TCP/IP configuration
Electronic mail services for moving mail through the network from the sender to the recipient
File servers that allow client computers to transparently share files
Print servers that allow printers to be centrally maintained and shared by all users
Servers on a TCP/IP network should not be confused with traditional PC LAN servers. Every Unix host on your network can be both a server and a client. The hosts on a TCP/IP network are "peers." All systems are equal, and the network is not dependent on any one server. All of the services discussed in this chapter can be installed on one or several systems on your network.
We begin with a discussion of name service. It is an essential service that you will certainly use on your network.