CentOS7 DHCP 服务搭建

一、实验环境

1、vmware12、俩台linux（ser  和  client ）、dhcp安装包。

二、操作流程

1、安装dhcp

2、配置dhcp的配置文件：  /etc/dhcp/dhcpd.conf

3、测试服务

三、实操如下

1、# yum -y install dhcp*            //安装dhcp，注意要带上*   在ser上操作。

2、# vim /etc/sysconfig/network-scripts/ifcfg-ens33-1           //在ser上配置网络ip地址，一般都是ens33

3、网络ip设置如下：

hwaddr=00:0c:29:03:ea:35
type=ethernet
proxy_method=none
browser_only=no
bootproto=static                   //改为static，表示静态地址
ipaddr=192.168.1.20                //改为和subnet 同网段的地址（此地址最好选择range之外的地址）
prefix=24                                  //改为和网路ip地址对应的子网掩码
gateway=192.168.1.1              //注意：此处网关必须设置和dhcp作用域里面的网关相同
dns1=8.8.8.8                             //dns设置正常的就可以
defroute=yes
ipv4_failure_fatal=no
ipv6init=yes
ipv6_autoconf=yes
ipv6_defroute=yes
ipv6_failure_fatal=no
ipv6_addr_gen_mode=stable-privacy
name=ens33
uuid=2d5fde3e-2e83-49af-b7d7-f326fc3a7001
onboot=yes                             //保证网卡处于yes 启动状态

⏩按键esc 输入：wq    保存退出。

#systemctl restart network         //重启网卡  （建议重启系统）

4、配置dhcp的配置文件： vim /etc/dhcp/dhcpd.conf

打开配置文件按照提示 #cp /usr/share/doc/dhcp*/dhcpd.conf.example /etc/dhcp/dhcpd.conf       //用示例文件覆盖配置文件

#vim /etc/dhcp/dhcpd.conf          //正式开始编辑配置文件，加底色的保留，其他的全部dd

# dhcpd.conf
#
# sample configuration file for isc dhcpd
#

# option definitions common to all supported networks...
option domain-name "example.org";                                                                             //作用域名
option domain-name-servers ns1.example.org, ns2.example.org;                                //dns

default-lease-time 600;                                                                                                  //默认租约时间
max-lease-time 7200;                                                                                                    //最大租约时间

# use this to enble / disable dynamic dns updates globally.
#ddns-update-style none;

# if this dhcp server is the official dhcp server for the local
# network, the authoritative directive should be uncommented.
#authoritative;

# use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).

log-facility local7;

# no service will be given on this subnet, but declaring it helps the
# dhcp server to understand the network topology.

subnet 10.152.187.0 netmask 255.255.255.0 {
}                                                                                                                       //声明网络拓扑

# this is a very basic subnet declaration.

subnet 10.254.239.0 netmask 255.255.255.224 {
  range 10.254.239.10 10.254.239.20;
  option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
}

# this declaration allows bootp clients to get dynamic addresses,
# which we don't really recommend.

subnet 10.254.239.32 netmask 255.255.255.224 {
  range dynamic-bootp 10.254.239.40 10.254.239.60;
  option broadcast-address 10.254.239.31;

  option routers rtr-239-32-1.example.org;
}

# a slightly different configuration for an internal subnet.
subnet 10.5.5.0 netmask 255.255.255.224 {                                                 //作用域网段
  range 10.5.5.26 10.5.5.30;                                                                          //地址池范围
  option domain-name-servers ns1.internal.example.org;                          //dns
  option domain-name "internal.example.org";                                          //作用域名
  option routers 10.5.5.1;                                                                             //网关，ser上面配置的网关和此网关要一致
  option broadcast-address 10.5.5.31;                                                        //广播地址
  default-lease-time 600;                                                                            //默认租约时间
  max-lease-time 7200;                                                                              //最大租约时间
}                                                                                                                      //创建一个子网地址池

# hosts which require special configuration options can be listed in
# host statements.   if no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.

host passacaglia {
  hardware ethernet 0:0:c0:5d:bd:95;
  filename "vmunix.passacaglia";
  server-name "toccata.fugue.com";
}

# fixed ip addresses can also be specified for hosts.   these addresses
# should not also be listed as being available for dynamic assignment.
# hosts for which fixed ip addresses have been specified can boot using
# bootp or dhcp.   hosts for which no fixed address is specified can only
# be booted with dhcp, unless there is an address range on the subnet
# to which a bootp client is connected which has the dynamic-bootp flag
# set.
host fantasia {
  hardware ethernet 08:00:07:26:c0:a5;
  fixed-address fantasia.fugue.com;
}

# you can declare a class of clients and then do address allocation
# based on that.   the example below shows a case where all clients

# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.

class "foo" {
  match if substring (option vendor-class-identifier, 0, 4) = "sunw";
}

shared-network 224-29 {
  subnet 10.17.224.0 netmask 255.255.255.0 {
    option routers rtr-224.example.org;
  }
  subnet 10.0.29.0 netmask 255.255.255.0 {
    option routers rtr-29.example.org;
  }
  pool {
    allow members of "foo";
    range 10.17.224.10 10.17.224.250;
  }
  pool {
    deny members of "foo";

range 10.0.29.10 10.0.29.230;
  }
}

⏩按键esc 输入：wq    保存退出。

#systemctl start dhcpd         //启动dhcp服务  

5、测试地址分发

首先将俩台虚拟系统ser 和 client 的网卡配置在同一个虚拟环境网络中，如下图

 

然后在client 上 修改网卡配置文件，bootproto=dhcp   删除静态地址后保存 重启网卡（也重启电脑）

同样在client 上安装dhcp服务

验证如下：

ifconfig 查看获取情况

route -n        //查看路由信息

也可以在ser上执行status 命令

#systemctl status dhcpd