Linux下DHCP服务器的搭建

1.关闭防火墙和SELinux

[root@ser5 /]# service iptables stop

[root@ser5 /]# vim /etc/selinux/config 

SELINUX=permissive（将 enforcing改为permissive）保存退出

2.准备两台虚拟机，一台作为服务器，一台作为客户机，配置两个主机的IP地址，使服务器和客户机能够通信

服务器：

[root@ser5 /]# vim /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

HWADDR=00:0c:29:a9:a0:68

TYPE=Ethernet

UUID=65d53814-182d-44ec-a0df-a0712c196aeb

ONBOOT=yes

NM_CONTROLLED=no

BOOTPROTO=none

IPADDR=192.168.4.5

NETMASK=255.255.255.0

IPV6INIT=no

USERCTL=no

客户机：

[root@pc205 /]# vim /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

HWADDR=00:0c:29:fe:4b:36

TYPE=Ethernet

UUID=65d53814-182d-44ec-a0df-a0712c196aeb

ONBOOT=yes

NM_CONTROLLED=no

BOOTPROTO=none

IPADDR=192.168.4.205

NETMASK=255.255.255.0

IPV6INIT=no

USERCTL=no

3.在服务器上安装dhcp服务

[root@ser5 /]# yum -y install dhcp

[root@ser5 /]# rpm -q dhcp  

dhcp-4.1.1-38.P1.el6.x86_64

确保dhcp服务成功安装

4.修改服务上dhcp的配置文件

[root@ser5 /]# vim /etc/dhcp/dhcpd.conf 

default-lease-time 600;    #默认租约时间600s

max-lease-time 7200;       #最大租约时间7200s

subnet 192.168.4.0 netmask 255.255.255.0{     #设置IP地址的作用域是192.168.4.0网段

 option routers  192.168.4.1;      #设置分配的网关

 option domain-name  "tarena.com";  #设置默认搜索域

 option domain-name-servers  202.106.0.20,8.8.8.8;  #设置DNS地址

 range 192.168.4.28 192.168.4.54;   #分配的IP地址范围

 range 192.168.4.128 192.168.4.200;

}

host fantasia {     #保留地址，给特定的主机分配IP地址

  hardware ethernet 00:0C:29:FE:4B:36;

  fixed-address 192.168.4.110;

}

注：在修改配置的文件的时候可以打开/usr/share/doc/dhcp*/dhcpd.conf.sample参考配置格式，同时也可以通过man dhcpd.conf查看配置文件的帮助手册

5.重启服务并设置开机自启动

[root@ser5 /]# service dhcpd restart

[root@ser5 /]# chkconfig dhcpd on

注：如果服务启动失败，一定是配置文件出错，可以去检查文档，或者去通过查看命令 less /var/log/messages 查看系统日志找出错误所在

Aug 12 19:25:18 ser5 dhcpd: /etc/dhcp/dhcpd.conf line 13: semicolon expected.

Aug 12 19:25:18 ser5 dhcpd:  range 

Aug 12 19:25:18 ser5 dhcpd:   ^

Aug 12 19:25:18 ser5 dhcpd: Configuration file errors encountered -- exiting

Aug 12 19:25:18 ser5 dhcpd: 

Aug 12 19:25:18 ser5 dhcpd: This version of ISC DHCP is based on the release available

Aug 12 19:25:18 ser5 dhcpd: on ftp.isc.org.  Features have been added and other changes

可知道错误在配置文件的第13行左右

更改配置文件后重新启动服务

6.通过客户机验证

[root@pc205 /]# dhclient -d eth0  

Internet Systems Consortium DHCP Client 4.1.1-P1

Copyright 2004-2010 Internet Systems Consortium.

All rights reserved.

For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:0c:29:fe:4b:36

Sending on   LPF/eth0/00:0c:29:fe:4b:36

Sending on   Socket/fallback

DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7 (xid=0x5bef1d5e)

DHCPOFFER from 192.168.4.5

DHCPREQUEST on eth0 to 255.255.255.255 port 67 (xid=0x5bef1d5e)

DHCPACK from 192.168.4.5 (xid=0x5bef1d5e)

bound to 192.168.4.110 -- renewal in 289 seconds.

通过该命令动态验证客户机获取IP地址的全过程，通过DHCP获得的地址是192.168.4.110

7.查看租约信息

服务器：

[root@ser5 /]# cat /var/lib/dhcpd/dhcpd.leases

# The format of this file is documented in the dhcpd.leases(5) manual page.

# This lease file was written by isc-dhcp-4.1.1-P1

lease 192.168.4.28 {

  starts 2 2014/08/12 06:50:35;

  ends 2 2014/08/12 07:00:35;

  tstp 2 2014/08/12 07:00:35;

  cltt 2 2014/08/12 06:50:35;

  binding state free;

  hardware ethernet 00:0c:29:fe:4b:36;

}

server-duid "\000\001\000\001\033|u\227\000\014)\251\240h";

可以查看到该服务器出租出去的IP地址信息

客户机：

[root@pc205 /]# cat /var/lib/dhclient/dhclient-ethN.leases

Internet Systems Consortium DHCP Client 4.1.1-P1

Copyright 2004-2010 Internet Systems Consortium.

All rights reserved.

For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:0c:29:fe:4b:36

Sending on   LPF/eth0/00:0c:29:fe:4b:36

Sending on   Socket/fallback

DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7 (xid=0x5bef1d5e)

DHCPOFFER from 192.168.4.5

DHCPREQUEST on eth0 to 255.255.255.255 port 67 (xid=0x5bef1d5e)

DHCPACK from 192.168.4.5 (xid=0x5bef1d5e)

bound to 192.168.4.110 -- renewal in 289 seconds.

^C

查看已获取的IP租约

Linux下DHCP服务器的搭建,古老的榕树,5-wow.com