DHCP配置[备忘]

参考

DHCP wiki , It's nice!!

DHCP 中文网

如下是转载博文:

DHCP全称动态主机配置协议（Dynamic Host Configuration Protocol）目的：减轻TCP/IP网络的规划、管理和维护的负担，解决IP地址空间缺乏问题。

DHCP服务相关概念和术语

/etc/dhcpd.conf文件通常包括：parameters(参数)、declaration（声明）、option（选项）。

parameters(参数)

declaration （声明）

option （选项）

/etc/dhcpd.conf 默认配置

ddns-update-style interim;  ##DHCP-DNS互动更新模式

ignore client-updates;

subnet 192.168.0.0 netmask 255.255.255.0 {

# --- default gateway

       option routers                  192.168.0.1;

       option subnet-mask        255.255.255.0;

       option nis-domain          "domain.org";

       option domain-name             "domain.org";

       option domain-name-servers      192.168.1.1;

       option time-offset           -18000;  # Eastern Standard Time

#     option ntp-servers           192.168.1.1;

#     option netbios-name-servers       192.168.1.1;

# --- 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 192.168.0.128 192.168.0.254;

       default-lease-time 21600;

       max-lease-time 43200;

       # we want the nameserver to appear at a fixed address

       host ns {

              next-server marvin.redhat.com;

              hardware ethernet 12:34:56:78:AB:CD;

              fixed-address 207.175.42.254;

       }

}

default-lease-time.默认的租期的时间，单位秒。

max-lease-time.定义最大租约时间，定义可以使用的最大值。

ddns-update-style.DHCP服务器可以动态升级的域名系统，该选项用来设置动态升级域名系统的模式，支持三种模式：ad-hoc,interim和none，none表示不支持自动升级模式。

option subnet-mask.定义分配给客户端的子网掩码。

option broadcast-address. 分配给客户端的广播地址。

option routers.定义分配给客户端的默认网关地址。

option domain-name-servers.定义分配给客户端的域名解析服务器地址，可以设置多个。

DHCP服务的客户租约文件dhcpd.conf！~

以前RHEL5中，该dhcpd.leases文件在/var/lib/dhcpd。

该文件格式：

# All times in this file are in UTC (GMT), not your local timezone.   This is

# not a bug, so please don't ask about it.   There is no portable way to

# store leases in the local timezone, so please don't request this as a

# feature.   If this is inconvenient or confusing to you, we sincerely

# apologize.   Seriously, though - don't ask.

# The format of this file is documented in the dhcpd.leases(5) manual page.

# This lease file was written by isc-dhcp-V3.0.5-RedHat

lease 192.168.1.25 {

  starts 3 2011/01/26 23:54:35;

  ends 4 2011/01/27 05:54:35;

  binding state active;

  next binding state free;

  hardware ethernet 00:0c:29:4a:bf:87;

  uid "\001\000\014)J\277\207";

  client-hostname "ds-a8a0cfe4a12d";

}

DHCP服务应用

共享作用域

shared-network语句告诉DHCP服务器某些IP子网共享同一个物理网络，任何一个在共享物理网络里的子网都必须声明在shared-network句里。

shared-network name {

[参数]

[声明]

｝

多作用域

网络中存在多个子网，只做一个DHCP服务器，在每一个子网设置DHCP中介代理。dhcp服务器的IP地址是192.168.1.254。

#全局配置。

       ddns-update-style interim;

       option subnet-mask                            255.255.255.0;

       option domain-name-servers             192.168.1.254;

       option time-offset                                -18000;

       default-lease-time                                416000;

       max-lease-time                                     632000;

#多作用域配置

       subnet 192.168.1.0 netmask 255.255.255.0  {

       option routers                                       192.168.1.254;

       option broadcast-address                    192.168.1.255;

       range dynamic-bootp     192.168.1.10  192.168.1.100;

       }

       subnet 192.168.2.0 netmask 255.255.255.0  {

       option routers                                       192.168.2.254;

       option broadcast-address                    192.168.2.255;

       range dynamic-bootp     192.168.2.10  192.168.2 .100;

       }

DHCP中继代理配置文件/etc/sysconfig/dhcrelay

       INTERFACES=”eth0”

       DHCPSERVERS=”192.168.1.254”

      然后启动DHCP中继代理服务

      service dhcrelay start