我的电脑连接两个网段(eth0:192.168.123.0/24，eth1:192.168.18.0/24)，系统中redhat 9，本文将把本机安装成两个网段DHCP服务器，仅作测试用……

1.下载 DHCP 3.0.3  点击下载

2.解压：

[root@Crazy bak]# tar zxvf dhcp-3.0.3.tar.gz
dhcp-3.0.3
dhcp-3.0.3/client
......
[root@Crazy bak]# cd dhcp-3.0.3
[root@Crazy dhcp-3.0.3]# ls
client  configure  dhcpctl  dst       LICENSE   Makefile.conf  minires  README  RELNOTES  site.conf
common  contrib    doc      includes  Makefile  Makefile.dist  omapip   relay   server    tests

3.安装：

[root@Crazy dhcp-3.0.3]# ./configure
System Type: linux-2.2
......
[root@Crazy dhcp-3.0.3]# make;make install

4.编辑/etc/dhcpd.conf(需手动创建)

root@Crazy etc]# vi dhcpd.conf

#全局设置

default-lease-time 259200;
max-lease-time     518400;
                                                                                                                        
option domain-name-servers 202.96.134.133,202.96.128.68;
                                                                                                                        
ddns-update-style ad-hoc;
              

#192.168.18.0/24网段，分配IP为：192.168.18.200-192.168.18.250                                                                                                          
subnet 192.168.18.0 netmask 255.255.255.0{
range 192.168.18.200 192.168.18.250;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.18.255;
option routers 192.168.18.1;
}
                                        

#192.168.123.0/24网段，分配IP为：192.168.123.200-192.168.123.250                                                                                 
subnet 192.168.123.0 netmask 255.255.255.0 {
range 192.168.123.200 192.168.123.250;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.123.255;
option routers 192.168.123.254;
}

#为网卡MAC为00:11:5B:10:24:9B分配一静态IP：192.168.18.251,做测试用
host crazy{
hardware ethernet 00:11:5B:10:24:9B;
fixed-address 192.168.18.251;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.18.255;
option routers 192.168.18.1;
}

5.试启动DHCP(默认启动程序为/usr/sbin/dhcpd)

[root@Crazy sbin]# dhcpd
Internet Systems Consortium DHCP Server V3.0.3
Copyright 2004-2005 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/
Can't open lease database /var/state/dhcp/dhcpd.leases: No such file or directory --
  check for failed database rewrite attempt!
Please read the dhcpd.leases manual page if you
don't know what to do about this.
 
If you did not get this software from ftp.isc.org, please
get the latest from ftp.isc.org and install that before
requesting help.
 
If you did get this software from ftp.isc.org and have not
yet read the README, please read it before requesting help.
If you intend to request help from the dhcp-server@isc.org
mailing list, please read the section on the README about
submitting bug reports and requests for help.
 
Please do not under any circumstances send requests for
help directly to the authors of this software - please
send them to the appropriate mailing list as described in
the README file.
 
exiting.

#启动出错,根据出错信息,Can't open lease database /var/state/dhcp/dhcpd.leases: No such file or directory --
#  check for failed database rewrite attempt!,建立/var/state/dhcp/dhcpd.leases

6.调试

[root@Crazy root]# touch /var/state/dhcp/dhcpd.leases

7.再启动DHCP

[root@Crazy sbin]# dhcpd
Internet Systems Consortium DHCP Server V3.0.3
Copyright 2004-2005 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/
Wrote 0 leases to leases file.
Listening on LPF/eth1/00:0f:3d:81:81:23/192.168.18/24
Sending on   LPF/eth1/00:0f:3d:81:81:23/192.168.18/24
Listening on LPF/eth0/00:11:2f:81:ea:28/192.168.123/24
Sending on   LPF/eth0/00:11:2f:81:ea:28/192.168.123/24
Sending on   Socket/fallback/fallback-net

#OK,如出现上面的信息,DHCP应该就已经正常启动了,可以通过以下命令查看是否已启动DHCP

[root@Crazy sbin]# netstat -utln
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 0.0.0.0:32768           0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:32769         0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:3306            0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:6000            0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:23              0.0.0.0:*               LISTEN
udp        0      0 0.0.0.0:32768           0.0.0.0:*
udp        0      0 0.0.0.0:517             0.0.0.0:*
udp        0      0 0.0.0.0:825             0.0.0.0:*
udp        0      0 0.0.0.0:67              0.0.0.0:*
udp        0      0 0.0.0.0:111             0.0.0.0:*
udp        0      0 0.0.0.0:631             0.0.0.0:*

#上面信息中的67就是DHCP所用端口,一切OK了

8.客户端进行测试(均为win2k的系统,IP设为自动)

#以下是192.168.18.0/24的测试信息

Ethernet adapter 本地连接:

        Connection-specific DNS Suffix  . :

        Description . . . . . . . . . . . : Realtek RTL8139 Family PCI Fast Ethernet NIC

        Physical Address. . . . . . . . . : 00-11-5B-10-24-9B

        Dhcp Enabled. . . . . . . . . . . : Yes

        Autoconfiguration Enabled . . . . : Yes

        IP Address. . . . . . . . . . . . : 192.168.18.250

#注意,此时IP为192.168.18.250,是因为在/etc/dhcpd.conf中没还没加入最后一段

        Subnet Mask . . . . . . . . . . . : 255.255.255.0

        Default Gateway . . . . . . . . . : 192.168.18.1

        DHCP Server . . . . . . . . . . . : 192.168.18.168

        DNS Servers . . . . . . . . . . . : 202.96.134.133

                                            202.96.128.68

        Lease Obtained. . . . . . . . . . : 2005年9月13日 15:42:39

        Lease Expires . . . . . . . . . . : 2005年9月16日 15:42:39

#以下是192.168.123.0/24的测试信息

Ethernet adapter 本地连接:

9.完成