Learning Red Hat Linux, Second Edition

Setting Up a DHCP Server

Managing the network configurations of the hosts on even a small network can be tedious. Administrators of large networks, including ISPs, have long used the DHCP service to centrally manage network configurations. Red Hat Linux includes a DHCP server that you can install in order to facilitate the management of your network. Hosts configured with DHCP clients can load their network configurations from the DHCP server at boot time, including such configuration items as:

• Hostname

• Domain name

• IP address

• Netmask

• Broadcast IP address

• Gateway IP address

• DNS server address

Installing the DHCP Server

Before installing the DHCP server, you should check whether your system’s network adapter is properly configured to support DHCP. To do so, issue the ifconfig command, as follows:

[root@localhost]# ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:A0:CC:25:8A:EC  
          inet addr:192.168.0.5  Bcast:192.168.255.255  
            Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:71910 errors:0 dropped:0 overruns:0 
            frame:0
          TX packets:108334 errors:0 dropped:0 overruns:0 
            carrier:0
          collisions:89 txqueuelen:100 
          Interrupt:11 Base address:0x6000

If your system’s network adapter is properly configured to support DHCP, the output of the ifconfig command will indicate that the adapter supports BROADCAST and MULTICAST. If the output doesn’t include these specifications, you must reconfigure or replace the network adapter. Fortunately, it’s rare that an adapter lacks these capabilities. ...