linux system installed DHCP server

Installing the DHCP Service
First, configure the network card, the card will become a static IP configuration steps are as follows:
NIC configuration file directory: / etc / sysyconfig / network-scripts Directory: there are corresponding ifcfg-eth0 configuration profile corresponding to the card
Content profile as follows: first row: device name DEVICE =                              Second row: the MCA address of                                the third line: TYPE = Ethernet Network type Ethernet                              fourth row: UUID                              fifth row: network manager (network linux carrying) ONBOOT = yes                              sixth line: network Manager (networkmanager)                              seventh line: dynamic or static DHCP dynamic static (none) static                              eighth line: IPADDR = 192.168.1.78                              ninth line: NETAMSJK = 255.255.255.0                              tenth line: gateway gATEWAY = 192.168.1.1                              eleventh line: DNS1 = 8.8.8.8 DNS2 = 114.114.114.114 Note: You can modify according to their needs After editing the input line mode: wq to save and exit
After the verification is complete, so that the configuration file to take effect, order: 1, / etc / init.d / network restart                                        Check DNS situation: 2, vim /etc/resolv.conf
The first step: Go to /etc/yum.repo.d folder, re-establish yum source file. Proceed as follows:
1, create a folder:	Example: mkdir zyl (name zyl folder)
2, the /etc/yum.repo.d asking about the price of all the files in the folder are moved to the new folder:	Command: mv C * zyl
3, create a configuration file directly into vim created:	Example: vim dvd.repo
4, in the configuration file is created which is written:	The first line: [casual Input] Second line: name = random input Third row: baseurl = file: /media/CentOS_6.9_Final Fourth row: gpgcheck = 0 The last line enter: wq to save and exit
5, yum install plug-ins:	Command: yum clean all
6, install the DHCP software:	Command: yum install dhcp Later to enter: y (carriage return)
7, enter the configuration file is modified:	Command: vim /etc/dhcp/dhcpd.conf (empty file)
8, import the configuration template in the empty file, directly modify more convenient:	Enter the command line mode: r /usr/share/doc/dhcp-4.1.1/dhcp.conf.sample
9, the file modification: only the portion reserved subnet 10.5.5.0 {}, dd delete all the rest.	1、subnet 10.5.5.0 表示工作网段 改为当前实验环境的网段 172.16.0.0 2、netmask 子网掩码：修改为实验要求的：255.25.0.0 3、range：地址池 修改 172.16.0.50 172.16.0.150 4、domain-name-servers：（dns）172.16.0.1  //将地址指向自己 5、domain-name：域名，没有域，可以删除不用了 6、routers：（网关）172.16.0.1   //将网关指向自己 7、下面一行没用删除 8、default-least-tim：（最小租期） 9、max-least-time：（最大租期）   //后面两个默认就行
10、启动dhcp为客户机分配IP地址：	启动命令： /etc/init.d/dhcpd start
11、查看67端口开放，说明开启成功：	查看命令：netstat -antpul | grep 6
报错排除
1、分析日志：	cat -f /var/log/messages
2、启动dhcp失败：	安装dhcp服务器的机子的IP地址，与要分配的ip池不相符。
3、dhcp配置文件	每行结尾要以分号结尾