CentOS 7 下搭建 DHCP

声明下啊：第一次发帖，菜鸟一枚，忘大牛多指点一二啊！

1.1.  安装篇

# mkdir  /mnt/cdrom/

# mount  /dev/cdrom  /mnt/cdrom

# cd/mnt  /cdrom/Packages/

# ls dhcp*

dhcp-4.2.5-27.el7.centos.x86_64.rpm 

dhcp-common-4.2.5-27.el7.centos.x86_64.rpm  

dhcp-libs-4.2.5-27.el7.centos.x86_64.rpm

 

# rpm -Uvhdhcp-4.2.5-27.el7.centos.x86_64.rpm

Preparing...                                   ################################# [100%]

Updating / installing...

  1:dhcp-12:4.2.5-27.el7.centos     ################################# [100%]

 

   Tips：如果你是高手或者电脑能联网，建议用yum安装，特别方便啊!

 # yum  -y  install dhcpd 

1.2.  配置

 

# rpm -qc  dhcp   //查询和DHCP相关的配置文件

/etc/dhcp/dhcpd.conf

/etc/dhcp/dhcpd6.conf

/etc/openldap/schema/dhcp.schema

/etc/sysconfig/dhcpd

/var/lib/dhcpd/dhcpd.leases

/var/lib/dhcpd/dhcpd6.leases

 

# cd  /etc/dhcp/

# cp  dhcpd.conf   dhcpd.conf.origin   //更改之前新备份，以备不测，

 

# cat  /etc/dhcp/dhcpd.conf 

# # DHCP Server Configuration file. #   see /usr/share/doc/dhcp*/dhcpd.conf.example #   see dhcpd.conf(5) man page #

查看示例文件 //我们可以根据这个example 快速的生成一个配置文件，而且不容易有错

# more   /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example

根据例子文件我们可以生成一个配置文件,可以配置两个网段的，一个网段就是一个subnet  

# vi/etc/dhcp/dhcpd.conf

option domain-name "lee.local"; option domain-name-servers 192.168.188.11, 192.168.188.12; default-lease-time 691200; max-lease-time 691200;   subnet 192.168.188.0 netmask 255.255.255.0 {   range 192.168.188.100 192.168.188.159;   range 192.168.188.170 192.168.188.253;   default-lease-time 259200;   max-lease-time 259200;   option routers 192.168.188.2; }   subnet 192.168.189.0 netmask 255.255.255.0 {   range 192.168.189.100 192.168.189.253;   option routers 192.168.189.2; }   host printer1 {   hardware ethernet 00:12:34:56:78:90;   fixed-address 192.168.188.111; }

 Tips ：default-lease-timetime;

                                 Time should be the length in seconds thatwill be assigned to a lease if the client requesting the leasedoes not ask fora  specific  expiration time.  This is used for both DHCPv4 and DHCPv6leases (it is also              known as the "valid lifetime" in DHCPv6).  The default is 43200 seconds.

                

max-lease-timetime;

Time  should be  the  maximum length in seconds that will beassigned to a lease.  If not defined,thedefault maximum lease time is 86400.  Theonly exception to this is that Dynamic BOOTP lease lengths,which are notspecified by the client, are not limited by this maximum.

# systemctl    start  dhcpd.service //启动服务，和以前的service dhcpd start的效果等同，

查看日志文件

Internet Systems Consortium DHCP Server 4.2.5 Copyright 2004-2013 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file Wrote 0 deleted host decls to leases file. Wrote 0 new dynamic host decls to leases file. Wrote 0 leases to leases file. Listening on LPF/eno16777728/00:0c:29:a4:2e:39/192.168.188.0/24 Sending on   LPF/eno16777728/00:0c:29:a4:2e:39/192.168.188.0/24 Sending on   Socket/fallback/fallback-net

配置DHCPD为自动启动, 这在CentOS 7上的新的变化 了

#systemctl  enable dhcpd.service  // 原来的是   chkconfig  dhcpd on 

# systemctlis-enabled dhcpd

enabled   //出现这个单词，证明已经设置为开机启动了。

1.3.  测试

   

在一台Windows客户机上进行测试

 

Tips：这个dns是我先前设置的，方便上网。

# tail   /var/lib/dhcpd/dhcpd.leases    //当客户机租用IP地址时，会在日志中看到

   

DHCPINFORM from 192.168.188.100 via eno16777728: not authoritative for subnet 192.168.188.0 DHCPREQUEST for 192.168.188.100 from 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728 DHCPACK on 192.168.188.100 to 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728 DHCPREQUEST for 192.168.188.100 from 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728 DHCPACK on 192.168.188.100 to 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728 DHCPREQUEST for 192.168.188.100 from 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728 DHCPACK on 192.168.188.100 to 00:0c:29:b3:a2:60 (TOMSRV1) via eno16777728

1.4.  总结

          DHCP的安装不是那么复杂，但是要注意，如果在虚拟机上安装的，记得把虚拟机的DHCP服务停了，要不然会出现和预期不一样的结果哟！

         DHCP服务器是一个比较特殊的服务器，要是在单位做实验的话，一定要小心啊，因为你一启动这个服务器，单位的交互机就会很生气哟！

          好了，不啰嗦了，就这么多吧，欢迎留言、转载、共同讨论  ~_~    ~_~