简单的dhcp 服务器(多vlan)

安装

yum install dhcp

 

占用的端口

dhcp服务器使用 UDP协议的 67 端口！

netstat -anulp | grep 67
udp        0      0 0.0.0.0:67                  0.0.0.0:*                               11634/dhcpd

 

配置文件，可以这样 cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf，每个subnet对应一个vlan 一共10个subnet，192.168.50.1-192.168.59.1

# cat /etc/dhcpd.conf
ddns-update-style interim;
ignore client-updates;
default-lease-time 86400;
max-lease-time 86400;

subnet 192.168.0.0 netmask 255.255.255.0 {

# --- default gateway
    range 192.168.0.10 192.168.0.126;
    option routers          192.168.0.1;
    option subnet-mask      255.255.255.0;

    option nis-domain       "domain.org";
    option domain-name      "test";
    option domain-name-servers  202.106.46.151,202.106.0.20;

    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;
    }
}

subnet 192.168.51.0 netmask 255.255.255.0 {
range 192.168.51.10 192.168.51.99;
option routers   192.168.51.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-ser7ers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.52.0 netmask 255.255.255.0 {
range 192.168.52.10 192.168.52.99;
option routers   192.168.52.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.53.0 netmask 255.255.255.0 {
range 192.168.53.10 192.168.53.99;
option routers   192.168.53.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.54.0 netmask 255.255.255.0 {
range 192.168.54.10 192.168.54.99;
option routers   192.168.54.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.55.0 netmask 255.255.255.0 {
range 192.168.55.10 192.168.55.99;
option routers   192.168.55.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.56.0 netmask 255.255.255.0 {
range 192.168.56.10 192.168.56.99;
option routers   192.168.56.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.57.0 netmask 255.255.255.0 {
range 192.168.57.10 192.168.57.99;
option routers   192.168.57.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.58.0 netmask 255.255.255.0 {
range 192.168.58.10 192.168.58.99;
option routers   192.168.58.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.59.0 netmask 255.255.255.0 {
range 192.168.59.10 192.168.59.99;
option routers   192.168.59.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

subnet 192.168.50.0 netmask 255.255.255.0 {
range 192.168.50.10 192.168.50.99;
option routers   192.168.50.1;
option subnet-mask  255.255.255.0;
option domain-name-servers      202.106.46.151,202.106.0.20;
#option netbios-name-servers     192.168.6.10,10.20.6.10;
option time-offset              -18000;
default-lease-time 86400;
max-lease-time 86400;
}

参数详解

参考了这篇文章

ddns-update-style interim;      //配置使用过渡性DHCP-DNS互动更新模式

ignore client-updates;       //忽略客户端更新

subnet 192.168.0.0 netmask 255.255.255.0 {    //为192.168.0.0子网分配地址

  option routers              192.168.0.1;   //为客户机指定默认网关

  option subnet-mask         255.255.255.0;  //为客户机指定子网掩码

  option nis-domain       "domain.org";//为客户机分配NIS域

  option domain-name      "domain.org";//为客户机分配DNS域

  option domain-name-servers   192.168.1.1;//分配的DNS地址

  range dynamic-bootp 192.168.0.128 192.168.0.254; //地址池

  default-lease-time   21600;          //默认租约时间（秒）

  max-lease-time      43200;           //最大租约时间（秒）

}



注：1)无论您创建一个还是多个作用域，其中必须要有一个作用域在subnet 之后的申明是该DHCP服务器的IP所在的子网地址，否则DHCP将无法启动，比如DHCP服务器的IP地址是192.168.1.1/24,那么必须有一个这样的作用域:

    subnet 192.168.1.0 mask 255.255.255.0 {

    }

    2)若有多个DNS，需要用逗号分开，一一列出，如

Option domain-name-servers   192.168.1.1,192.168.1.2;

3)若为某一网段分配的地址并不是连续的，我们只需创建多条地址池记录，如：

  Range dynamic-bootp 192.168.1.1 192.168.1.40;

  Range dynamic-bootp 192.168.1.61 192.168.1.254;

此时，便可分配192.168.1.0网段中的除去192.168.1.41-192.168.1.60范围的地址。



（2）主机的绑定

    对于有些客户机，我们总希望它们每次获取的IP都是固定的，这时可以进行主机绑定设置，

 host  ns{

                next-server marvin.redhat.com; //设置用于定义服务器从引导文件中装入的主机名，用于无盘工作站

                hardware ethernet 12:34:56:78:AB:CD; //要绑定的DHCP客户机的MAC地址

                fixed-address 207.175.42.254; //要固定分配给DHCP客户机的IP地址

        }



（3）超级作用域

超级作用域主要用在给不同网段的客户机分配地址的情况，配置时，只需要将多个作用域放在shared-network中即可，其形式如下：

shared-network 名称{

subnet 子网地址 netmask 子网掩码 {};

subnet 子网地址 netmask 子网掩码 {};

......

}



（4）服务器选项

如果dhcp中存在多个作用域，而且每个作用域均有一些相同的配置，这时我们可以减少配置工作量，将那些相同的配置统一放在超级作用域之外，如：

shared-network 名称 {};

default-lease-time   21600;

max-lease-time      43200;

这样会为不同作用域的主机均设置相同的租约。



（5）按照客户机的类别分配IP地址

将客户机按照某种属性分类，根据不同的属性类分配不同范围的地址，如：

subnet 192.168.10.0 network 255.255.255.0 {

class  "vm" {

match if substring (hardware,1,3)=00:0c:29

}                         //根据MAC定义匹配虚拟机的类

pool {

allow members of "vm";

range 192.168.10.10 192.168.10.50;

}                         //为匹配"vm"的客户机分配IP

pool {

deny members of "vm";

range 192.168.10.100 192.168.10.110;

}

}                             //为不匹配"vm"的客户机分配IP



4、语法检查

#service dhcpd configtest

5、启动DHCP服务

#service dhcpd start

 

dhcpd 日志

相关日志记录在 /var/log/messages,比如下面的！

tail /var/log/messages
Sep 22 19:29:08 gw-new dhcpd: DHCPDISCOVER from 00:16:d3:46:0b:38 via 192.168.50.1
Sep 22 19:29:09 gw-new dhcpd: DHCPOFFER on 192.168.50.99 to 00:16:d3:46:0b:38 (BJBXHH) via 192.168.50.1
Sep 22 19:29:09 gw-new dhcpd: DHCPREQUEST for 192.168.50.99 (192.168.0.1) from 00:16:d3:46:0b:38 (BJBXHH) via 192.168.50.1
Sep 22 19:29:09 gw-new dhcpd: DHCPACK on 192.168.50.99 to 00:16:d3:46:0b:38 (BJBXHH) via 192.168.50.1
Sep 22 19:44:04 gw-new dhcpd: DHCPREQUEST for 192.168.0.125 from 00:22:68:1c:83:c3 (KevinChia) via 192.168.58.1: ignored (not authoritative).

使用 dhcpd.log 记录日志

vim /etc/syslog.conf
local0.*                        /var/log/dhcpd.log #添加此行

vim /etc/dhcpd.conf
log-facility local0;                               #添加此行

touch /var/log/dhcpd.log                           #建立一个空文件

/etc/init.d/syslog restart                         #重启syslog
Shutting down kernel logger:                               [  OK  ]
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
Starting kernel logger:                                    [  OK  ]
/etc/init.d/dhcpd restart                          #重启dhcpd
Starting dhcpd:                                            [  OK  ]

tail /var/log/dhcpd.log
Sep 23 16:28:20 one dhcpd: Internet Systems Consortium DHCP Server V3.0.5-RedHat
Sep 23 16:28:20 one dhcpd: Copyright 2004-2006 Internet Systems Consortium.
Sep 23 16:28:20 one dhcpd: All rights reserved.
Sep 23 16:28:20 one dhcpd: For info, please visit http://www.isc.org/sw/dhcp/
Sep 23 16:28:20 one dhcpd: Wrote 10 leases to leases file.
Sep 23 16:28:20 one dhcpd: Listening on LPF/eth0/e2:ab:72:55:e2:e2/192.168.6/24
Sep 23 16:28:20 one dhcpd: Sending on   LPF/eth0/e2:ab:72:55:e2:e2/192.168.6/24
Sep 23 16:28:20 one dhcpd: Sending on   Socket/fallback/fallback-net

 

转载于:https://blog.51cto.com/dngood/672222