There are two key services that help your Linux computer communicate on a TCP/IP network such as the Internet: DNS and DHCP. This chapter showed you how to configure clients and servers for each service.
A DNS server is a database of FQDN and IP addresses. You can configure master, slave, caching-only, or forwarding DNS servers. Red Hat encourages the use of redhat-config-bind to configure the main DNS configuration files, /etc/named.conf and several files in /var/named . If you use this tool, add special configuration options to /etc/named.custom . Once you ve configured the server, you can start the named daemon, which controls DNS, with the service named start command.
Generally, no special configuration is required to set up a DNS client. Normally, a DNS client will search through /etc/ hosts before moving to the DNS servers identified in /etc/resolv.conf .
A DHCP server enables you to manage the IP addresses on your network. You can also set up other basic network information in the /etc/dhcpd.conf configuration file, such as gateways, DNS servers, NIS servers, and even SMTP servers. As long as the DHCP server computer has a network card with an IP address, you can start the DHCP server with the service named dhcpd command. Configuring a gateway computer to transfer DHCP messages between networks is possible with the dhcrelay daemon. Once you ve set up a DHCP server, you can lease an address with the dhclient command. Leased addresses are stored in a /var/lib/dhcp/dhcpd.leases database.
Configuring DHCP clients is fairly easy; the key file is the configuration file for your network card in the /etc/sysconfig/network-scripts directory. If there is a DHCP server for your LAN, you can get your IP addressing information for it immediately with the dhclient command.
In the next chapter , we ll look at the two major print systems for Linux: the Common Unix Print System (CUPS) and the Line Print Daemon (LPD).