1、查询dhcp有没有被安装，如下没有被安装
[zfp@localhost ~]$ rpm -q dhcp
package dhcp is not installed
[zfp@localhost ~]$
2、查询yum网络源中有关dhcp的rpm包
[root@localhost zfp]# yum list |grep dhcp
dhcp.x86_64 12:4.1.1-53.P1.el6.centos.1 updates
dhcp-common.x86_64 12:4.1.1-53.P1.el6.centos.1 updates
dhcp-devel.i686 12:4.1.1-53.P1.el6.centos.1 updates
dhcp-devel.x86_64 12:4.1.1-53.P1.el6.centos.1 updates
sblim-cmpi-dhcp.i686 1.0-1.el6 base
sblim-cmpi-dhcp.x86_64 1.0-1.el6 base
sblim-cmpi-dhcp-devel.i686 1.0-1.el6 base
sblim-cmpi-dhcp-devel.x86_64 1.0-1.el6 base
sblim-cmpi-dhcp-test.x86_64 1.0-1.el6 base
3、安装dhcp
[root@localhost zfp]# yum install dhcp -y
4、查询是否安装成功
[root@localhost zfp]# rpm -q dhcp
dhcp-4.1.1-53.P1.el6.centos.1.x86_64
[root@localhost zfp]#
查询安装的含有dhcp字符串包名的rpm包
[root@localhost zfp]# rpm -qa |grep dhcp
dhcp-common-4.1.1-53.P1.el6.centos.1.x86_64
dhcp-4.1.1-53.P1.el6.centos.1.x86_64
5、修改配置文件/etc/dhcp/dhcpd.conf
不同的发行版不一定是/etc/dhcp/dhcpd.conf这个文件，也可能是/etc/dhcpd.conf，centos6.5发行版是/etc/dhcp/dhcpd.conf
[root@localhost zfp]#vim /etc/dhcp/dhcpd.conf
ddns-update-style interim; #表示dhcp服务器和dns服务器的动态信息更新模式
ignore client-updates; #忽略客户端更新
subnet 10.10.10.0 netmask 255.255.255.0 { #意思是我所分配的ip地址所在的网段为192.168.145.0 子网掩码为255.255.255.0
range 10.10.10.100 10.10.10.200; #租用IP地址的范围
option domain-name-servers 8.8.8.8,114.114.114.114;
option domain-name "example.org";
option routers 10.10.10.1; #路由器地址，这里是当前 dhcp 机器的IP地址
option subnet-mask 255.255.255.0; #子网掩码
default-lease-time 600; #默认租约时间
max-lease-time 7200; #最大租约时间
#host myhost { #设置主机声明
#hardware ethernet 08:00:27:2C:30:8C; #指定dhcp客户的mac地址
#fixed-address 192.168.145.155; #给指定的mac地址分配ip
# }
}
6、创建虚接口并重启网络
cp ifcfg-eth0:1 ifcfg-eth0:1
vi ifcfg-eth0:1
DEVICE=eth0:1
HWADDR=00:0C:29:AD:F8:B7
TYPE=Ethernet
UUID=d60f7bad-0f18-420a-8e19-3e361f8ffed4
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=static
IPADDR=10.10.10.1
NETMASK=255.255.255.0
service network restart
[root@localhost zfp]#vim /etc/sysconfig/dhcpd
DHCPDARGS=eth0:1 #指定在eth0:11虚接口上提供dhcpserver服务
7、开启dhcp服务
root@localhost zfp]#service dhcpd start （或者/etc/init.d/dhcpd start）
[root@localhost zfp]# service dhcpd status
dhcpd (pid 4478) 正在运行...
[root@localhost zfp]#
设置开机启动dhcpd
chkconfig dhcpd on
如果有报错，查看dhcp服务开启的时候，报什么错误cat /var/log/messages 或者tail -f /var/log/messages &
如下是正常开启dhcp服务的log信息
Jan 9 04:50:38 localhost dhcpd: Internet Systems Consortium DHCP Server 4.1.1-P1
Jan 9 04:50:38 localhost dhcpd: Copyright 2004-2010 Internet Systems Consortium.
Jan 9 04:50:38 localhost dhcpd: All rights reserved.
Jan 9 04:50:38 localhost dhcpd: For info, please visit https://www.isc.org/software/dhcp/
Jan 9 04:50:38 localhost dhcpd: Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
Jan 9 04:50:38 localhost dhcpd: Wrote 3 leases to leases file.
Jan 9 04:50:38 localhost dhcpd: Listening on LPF/eth0:1/00:0c:29:ad:f8:b7/10.10.10.0/24
Jan 9 04:50:38 localhost dhcpd: Sending on LPF/eth0:1/00:0c:29:ad:f8:b7/10.10.10.0/24
Jan 9 04:50:38 localhost dhcpd: Sending on Socket/fallback/fallback-net
Jan 9 04:50:40 localhost dhcpd: DHCPREQUEST for 10.10.10.100 from a0:9d:86:fc:89:12 via eth0:1
Jan 9 04:50:40 localhost dhcpd: DHCPACK on 10.10.10.100 to a0:9d:86:fc:89:12 via eth0:1
[root@localhost network-scripts]#
[root@localhost network-scripts]# netstat -anulp | grep :67
udp 0 0 0.0.0.0:67 0.0.0.0:* 4591/dhcpd
[root@localhost network-scripts]#
如果启动的时候出现错误（Can't chown new lease file: Operation not permitted），需修改/etc/rc.d/init.d/dhcpd文件中的
user=dhcpd
group=dhcpd
为
user=root
group=root
再启动尝试
如下FORWARD链中REJECT的规则，阻止了数据报文的转发，进行删除iptables -D FORWARD 1，然后service iptables save保存到配置
iptables -nvL FORWARD
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
389 23343 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
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