在DHCP服务器上执行以下脚本
#!/bin/sh
INSTALL_DIR=`pwd`
rpm -ivh dhcp-3.0.5-3.el5.i386.rpm   &>/dev/null
echo 'ddns-update-style none;
        default-lease-time 36000000;
        max-lease-time 43200000;
        option domain-name              "xxx.com";
        option domain-name-servers      61.134.1.4;
subnet 172.16.100.0 netmask 255.255.255.0 {
        range dynamic-bootp 172.16.100.10 172.16.100.254;
        option routers                  172.16.100.1;
        option subnet-mask              255.255.0.0;
        host manager {
                next-server marvin.redhat.com;
                hardware ethernet 12:34:56:78:AB:CD;
                fixed-address 172.16.100.88;
        }
}
subnet 192.168.1.0 netmask 255.255.255.0 {
        range dynamic-bootp 192.168.1.111 192.168.1.191;
        option routers                  192.168.1.1;
        option subnet-mask              255.255.255.0;
        host manager1 {
                next-server marvin.redhat.com;
                hardware ethernet 12:34:56:78:AB:CD;
                fixed-address 172.16.100.88;
        }
}
subnet 10.1.10.0 netmask 255.255.255.0 {
        range dynamic-bootp 10.1.10.200 10.1.10.250;
        option routers                  10.1.10.1;
        option subnet-mask              255.0.0.0;
        host manager2 {
                next-server marvin.redhat.com;
                hardware ethernet 12:34:56:78:AB:CD;
                fixed-address 172.16.100.88;
        }
}' > /etc/dhcpd.conf
echo '# Command line options here
DHCPDARGS="eth0" ' >/etc/sysconfig/dhcpd
service dhcpd restart   &>/dev/null
rm -rf $INSTALL_DIR/*
 
在dhcp中继服务器上执行下面的脚本
#!/bin/sh
INSTALL_DIR=`pwd`
rpm -ivh dhcp-3.0.5-3.el5.i386.rpm  &>/dev/null
vi /etc/sysctl.conf << EOF   &>/dev/null
/net.ipv4.ip_forward = 0
:s/0/1/
:wq
EOF
sysctl -p    &>/dev/null
echo '# Command line options here
INTERFACES="eth0 eth1 eth2"
DHCPSERVERS="172.16.100.10" ' > /etc/sysconfig/dhcrelay
service dhcrelay start  &>/dev/null
chkconfig --level 35 dhcrelay on 
rm -rf INSTALL_DIR/dhcrelay.sh
 
注意：在做之前需要准备DHCP软件包（RPM包），可以下载最新版本的，也可以通过挂载Red Hat 5的光盘，然后找到DHCP软件包，进行安装。脚本里面的配置你只需根据实际情况进行修改即可使用。