DHCP 动态主机设置协议

dhcp:

功能：

给其它主机分配网络参数: IP/DNS/GW

C/S

端口67 / 68

工作原理：

配置过程：

DHCP服务器

1、拥有固定IP

2、定义将租出去的IP地址范围

1、安装实现DHCP协议的程序包

]# ls /mnt/Server/dhcp-3.0.5-23.el5.i386.rpm

]# mount -o loop rhel5u5.iso /mnt/

]# yum -y install dhcp

2、根据需要修改配置文件

]# vim /etc/dhcpd.conf

]# ls /usr/share/doc/dhcp*/dhcpd.conf.sample

]# cp /usr/share/doc/dhcp*/dhcpd.conf.sample /etc/dhcpd.conf

cp：是否覆盖“/etc/dhcpd.conf”? y

[root@localhost ftp]# cat /etc/dhcpd.conf

ddns-update-style interim;

ignore client-updates;

声明子网，要求必须与当前网卡ip在一个网段

subnet 192.168.1.0 netmask 255.255.255.0 {

option routers 192.168.1.254; 定义网关，客户端获得ＤＨＣＰ提供的服务后，客户的网卡网关与之相同

option subnet-mask 255.255.255.0;

option domain-name-servers 202.106.0.45,202.206.0.20; 定义DNS的IP，DNS本机IP地址

option time-offset -18000; # Eastern Standard Time

option ntp-servers 192.168.1.254; 定义时间服务器IP

range dynamic-bootp 192.168.1.1 192.168.1.253;定义要分配给客户端的IP地址范围

default-lease-time 21600; 定义租约最小时间为6小时

max-lease-time 43200; 定义最大租约时间为12小时

# we want the nameserver to appear at a fixed address

host host1 { 给相应MAC的主机分配固定IP

hardware ethernet 00:e0:4c:41:95:c5;

fixed-address 192.168.1.110;

}

host host2 {

hardware ethernet 00:e0:4c:cf:01:7b;

fixed-address 192.168.1.120;

}

}

3、启动服务

]# service dhcpd restart

如果失败，tail /var/log/messages

4、找客户端测试

[root@localhost ftp]# dhclient eth0

Internet Systems Consortium DHCP Client V3.0.5-RedHat

Copyright 2004-2006 Internet Systems Consortium.

All rights reserved.

For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/eth0/00:ee:ee:00:0a:76

Sending on LPF/eth0/00:ee:ee:00:0a:76

Sending on Socket/fallback

DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7

DHCPOFFER from 192.168.1.254

DHCPREQUEST on eth0 to 255.255.255.255 port 67

DHCPACK from 192.168.1.254

bound to 192.168.1.248 -- renewal in 9620 seconds.