一步轻松搞定DHCP服务器.

 搭建一个DNS服务器35秒那么DHCP服务器呢.9秒就足能够了

一个公司有大量的主机时一个一个的配置IP子网DNS.还不得配到吐血.有了DHCP服务器出现就能够迎刃而解了,.它能够动态分配IP.大大减小了管理员的工做量,并且能避免IP的冲突,而且节约IP(当IP不够用时).可是如今你拉一条线人电信就给你配好了DHCP. 或者说我直接买个猫里面就有DHCP功能. 还用本身搭建吗??,

若是有多个部门的话.并且每一个部门的网段都不能同样,这时用DHCP服务器就能够大显身手了,这里单网段的DHCP服务器和多网段的DHCP服务器都搞定.

废话很少说,开始搭建.

这个单网段的DHCP服务器我就不用拓扑图了

简单画了个多网段的DHCP服务器拓扑:

 

搭建单网段的DHCP服务器:

说明一点:DHCP服务器linux和windows下还不同.分配IP的时候windows下是由小到大分配.而linux下是由大到小分配的

这里提供脚本绝对可行。执行完你的DHCP服务器就能够说OK了

#!/bin/bash mkdir /mafei mount /dev/cdrom  /mafei cd /mafei/Server rpm -ivh dhcp-3.0.5-3.el5.i386.rpm cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf  << MAFEI y MAFEI vi /etc/dhcpd.conf  << MAFEIFEI :%s/192.168.0.0/192.168.142.0/g :%s/192.168.0.128 192.168.0.254/192.168.142.129 192.168.142.254/g :%s/192.168.0.1/192.168.142.127/g :%s/192.168.1.1/192.168.142.128/g :wq MAFEIFEI service dhcpd restart chkconfig –level 35 dhcpd  on

 

下面提供具体操做过程

建立目录将光盘挂载到指定目录下在进行dhcp软件包的安装

 

[root@server ~]# mkdir /mafei [root@server ~]# mount /dev/cdrom /mafei mount: block device /dev/cdrom is write-protected, mounting read-only     [root@server Server]# rpm -ivh dhcp-3.0.5-3.el5.i386.rpm   warning: dhcp-3.0.5-3.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186 Preparing...                ########################################### [100%]    1:dhcp                   ########################################### [100%]

用模板将原文件覆盖掉而后修改模板文件

要作多个网的话必须在原来DHCP服务器上添加一个要发布的网段，

 

[root@server Server]# cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf cp：是否覆盖“/etc/dhcpd.conf”? y [root@server Server]# vi /etc/dhcpd.conf   ddns-update-style none;    //关闭动态DNS更新模式   ignore client-updates;   subnet 192.168.142.0 netmask 255.255.255.0 {     //要发布的网段（第一个要和本身一个网段不然会出错得）       # --- default gateway           option routers                  192.168.142.127;  //要指定的网关         option subnet-mask              255.255.255.0;     //网关子网掩码           option nis-domain               "domain.org";                  option domain-name              "domain.org";        //默认搜索区域         option domain-name-servers      192.168.142.128;        //DNS服务器的IP           option time-offset              -18000; # Eastern Standard Time   #       option ntp-servers              192.168.142.128; #       option netbios-name-servers     192.168.142.128; # --- Selects point-to-point node (default is hybrid). Don't change this unless # -- you understand Netbios very well #       option netbios-node-type 2;           range dynamic-bootp 192.168.142.129 192.168.142.254;  //要分布的IP地址范围         default-lease-time 21600;                         //默认租约时间         max-lease-time 43200;                            //最大租约时间           # we want the nameserver to appear at a fixed address           host ns {              //为某个客户机指定特定IP (ns为自定义名称,.在本文件中惟一存在)                 next-server marvin.redhat.com;                   hardware ethernet 12:34:56:78:AB:CD;  //绑定的客户机max地址                 fixed-address 207.175.42.254;       //为客户机分配的IP地址         } } subnet 1.1.1.0 netmask 255.255.255.0 {           option routers                  1.1.1.1;         option subnet-mask              255.255.255.0;         range dynamic-bootp 1.1.1.3 1.1.1.222;         default-lease-time 21600;         max-lease-time 43200; }

启动DHCP服务使服务器开始运行。

[root@server ~]# service dhcpd restart 关闭 dhcpd：                                               [失败] 启动 dhcpd：                                               [肯定]

 

 

 

 

默认仍是不要指了指了还容易出错因此推荐不要作任何配置若是作dhcp中继的话必须指

[root@server ~]# vi /etc/sysconfig/dhcpd # Command line options here DHCPDARGS=

在客户机上先试一下能不能获取到IP 能的话再作中继否则 连DHCP服务器都没搭出来后面也不用作了

仍是老规矩先随便给同一网段的IP看是否能ping通，别犯低级错误。

 

搭建多网段的DHCP服务器  

其实比DHCP服务器的搭建多了一步就是在DHCP主配置文件中后面添加一个要指派的网段（这个网段必须和DHCP中继服务器上的另外一个网卡在一个网段啊）

其实就是拷贝一下模板将原来的文件覆盖掉而后再进行修改就好了 必要的时候指定一下使用哪一个接口就搞定了

注意一点:DHCP服务器的网关必须指向DHCP中继服务器的IP不然会获取不到IP的

一样提供脚本一步搞定.连ip也OK了

#!/bin/bash LOCALIP=192.168.142.128 NETMASK=255.255.255.0 DHCPIP1=192.168.142.0 DHCPIP2=192.168.1.0 DHCPIP3=192.168.2.0 DHCPIPRANGE="192.168.142.130 192.168.142.254" DHCPIPRANGE2="192.168.1.5 192.168.1.253" DHCPIPRANGE3="192.168.2.5 192.168.2.253" DHCPROUTE=192.168.142.127 DHCPROUTE2=192.168.1.1 DHCPROUTE3=192.168.2.1 DNSIP=192.168.142.128 DNSNAME=www.mafei.com NETMASK=255.255.255.0 ETH0=/etc/sysconfig/network-scripts/ifcfg-eth0 echo "# Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE]" > $ETH0 echo "DEVICE=eth0" >> $ETH0 echo "ONBOOT=yes" >> $ETH0 echo "TYPE=Ethernet" >> $ETH0 echo "IPADDR=$LOCALIP" >> $ETH0 echo "NETMASK=$NETMASK" >> $ETH0 echo "GATEWAY=$DHCPROUTE" >> $ETH0 service network restart   mkdir /mafei mount /dev/cdrom /mafei cd /mafei/Server rpm -ivh /mafei/Server/dhcp-3.0.5-3.el5.i386.rpm cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf << MAFEI y MAFEI vi /etc/dhcpd.conf << MYMAFEI :%s/ddns-update-style interim/ddns-update-style none :%s/subnet 192.168.0.0 netmask 255.255.255.0/subnet $DHCPIP1 netmask 255.255.255.0 :%s/192.168.0.1;/$DHCPROUTE; :%s/range dynamic-bootp 192.168.0.128 192.168.0.254;/range dynamic-bootp $DHCPIPRANGE; :wq! MYMAFEI service dhcpd restart   echo "subnet $DHCPIP2 netmask 255.255.255.0 {" >> /etc/dhcpd.conf echo "        option routers                  $DHCPROUTE2;" >> /etc/dhcpd.conf echo "        option subnet-mask              $NETMASK;" >> /etc/dhcpd.conf echo "#        option nis-domain               "$DNSNAME";" >> /etc/dhcpd.conf echo "#        option domain-name              "$DNSNAME";" >> /etc/dhcpd.conf echo "#        option domain-name-servers      $DNSIP;" >> /etc/dhcpd.conf echo "        range dynamic-bootp $DHCPIPRANGE2;" >> /etc/dhcpd.conf echo "        default-lease-time 21600;" >> /etc/dhcpd.conf echo "        max-lease-time 43200;" >> /etc/dhcpd.conf echo "}" >> /etc/dhcpd.conf       service dhcpd restart   echo "subnet $DHCPIP3 netmask 255.255.255.0 {" >> /etc/dhcpd.conf echo "        option routers                  $DHCPROUTE3;" >> /etc/dhcpd.conf echo "        option subnet-mask              $NETMASK;" >> /etc/dhcpd.conf echo "#        option nis-domain               "$DNSNAME";" >> /etc/dhcpd.conf echo "#        option domain-name              "$DNSNAME";" >> /etc/dhcpd.conf echo "#        option domain-name-servers      $DNSIP;" >> /etc/dhcpd.conf echo "        range dynamic-bootp $DHCPIPRANGE3;" >> /etc/dhcpd.conf echo "        default-lease-time 21600;" >> /etc/dhcpd.conf echo "        max-lease-time 43200;" >> /etc/dhcpd.conf echo "}" >> /etc/dhcpd.conf service dhcpd restart chkconfig --level 35 dhcpd on

DHCP中继服务器的搭建  

在中继服务器上作的配置：

1.       开启服务器的路由转发功能

编辑“/etc/dhcpd.conf”将net.ipv4.ip_forward = 0改成net.ipv4.ip_forward = 1开启路由功能，并执行sysctl –p 命令使配置生效

[root@server Server]# vi /etc/sysctl.conf net.ipv4.ip_forward = 1 [root@server Server]# sysctl -p net.ipv4.ip_forward = 1 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.default.accept_source_route = 0 kernel.sysrq = 0 kernel.core_uses_pid = 1 net.ipv4.tcp_syncookies = 1 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 4294967295 kernel.shmall = 268435456

 

 

 

若是没有这个文件的话不用慌，那是你DHCP软件包没安装上。再安一遍就搞定了

[root@server Server]# vi /etc/sysconfig/dhcrelay # Command line options here INTERFACES="eth0  eth1 eth2" DHCPSERVERS="192.168.142.127"

 

 

 

[root@server Server]# service dhcrelay restart Shutting down dhcrelay:                                    [FAILED] Starting dhcrelay: Internet Systems Consortium DHCP Relay Agent V3.0.5-RedHat Copyright 2004-2006 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ Listening on LPF/eth1/00:0c:29:c1:ef:89 Sending on   LPF/eth1/00:0c:29:c1:ef:89 Listening on LPF/eth0/00:0c:29:c1:ef:7f Sending on   LPF/eth0/00:0c:29:c1:ef:7f Sending on   Socket/fallback                                                            [  OK  ] [root@server Server]# chkconfig --level 35 dhcrelay on

 

调整客户机的网段。我用的是虚拟机因此你用跳到和中继的2网卡在同一网段便可若是在现实中直接跳到另外一个路由口上就 行了、

 

 

 

 

 

 

 

3.       启动dhcrelay中继服务程序。并设置开机自动启动

 

2.       设置容许DHCP中继数据的接口及DHCP服务器的ip地址

 

指定DHCP服务器提供服务的接口