1.DHCP简介：
DHCP（Dynamic Host Configuration Protocol，动态主机配置协议）通常被应用在大型的局域网络环境中，主要作用是集中的管理、分配IP地址，使网络环境中的主机动态的获得IP地址、Gateway地址、DNS服务器地址等信息，并能够提升地址的使用率。
2.DHCP服务器简介:
DHCP服务器指的是由服务器控制一段IP地址范围，客户端登录服务器时就可以自动获得服务器分配的IP地址和子网掩码。
3.安装DHCP软件
[root@localhost Server]# rpm -ivh dhcp-3.0.5-21.el5.x86_64.rpm
4.安装后DHCP生成的软件文件路径（部分）
[root@localhost Server]# rpm -ql dhcp
/etc/dhcpd.conf
/etc/rc.d/init.d/dhcpd
/etc/rc.d/init.d/dhcrelay
/etc/sysconfig/dhcpd
/etc/sysconfig/dhcrelay
/usr/bin/omshell
/usr/sbin/dhcpd（启动脚本）
/usr/sbin/dhcrelay
/usr/share/doc/dhcp-3.0.5/api+protocol
/usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample（重点文件）
/var/lib/dhcpd/dhcpd.leases （租约文件）
5.配置文件说明
说明：CentOS 5.X以前的配置文件路径 是/etc/dhcpd.conf 新版的配置文件路径 是/etc/dhcp/dhcpd.conf
[root@localhost Server]#cat /etc/dhcpd.conf
# DHCP Server Configuration file.
# see /usr/share/doc/dhcp*/dhcpd.conf.sample （说明配置文件的模版路径 ）
[root@localhost Server]# cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf
[root@localhost Server]# cat /etc/dhcpd.conf
#这部分是全局设置
default-lease-time 259200; 租约时间
max-lease-time 518400; 最大租约时间
option domain-name"zzhz.com"; 设置，/etc/resolv.conf
option domain-name-servers IP1, IP2; DNS设置，会修改客户端的/etc/resolv.conf
ddns-update-style none;
ddns-update-style interim;
ignore client-updates：
option routers IP; 默认路由：
#subnet ：指定子网作用域(动态IP)
subnet 192.168.0.0 netmask 255.255.255.0 {
# --- default gateway
option routers 192.168.0.1;
option subnet-mask 255.255.255.0;
option nis-domain "domain.org";
option domain-name "domain.org";
option domain-name-servers 192.168.1.1;
option time-offset -18000; # Eastern Standard Time
# option ntp-servers 192.168.1.1;
# option netbios-name-servers 192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
# option netbios-node-type 2;
range dynamic-bootp 192.168.0.128 192.168.0.254;
default-lease-time 21600;
max-lease-time 43200;
# 固定IP地址设置
host ns {
next-server marvin.redhat.com;
hardware ethernet 12:34:56:78:AB:CD;
fixed-address 207.175.42.254;
}
}