DHCP-实验实施过程
实验案例：构建DHCP服务器
需求描述
- DHCP 服务器的主机名为 dhcpsvr.kgc.com,IP 地址为 192.168.4.11/24.
- 用于给局域网内各主机自动分配的IP地址范围为192.168.4.20,192.168.4.200.
- 局域网内各主机使用的默认地址为192.168.4.1.
- 局域网内各主机使用的DNS服务器地址分别为192.168.4.2和192.168.4.3,DNS 服务器的主机名分别为ns1.kgc.com和ns2.kgc.com。
- 网络打印机设备（可在网络内另找一台Windows主机,执行“ipconfig /all”命令查知其MAC地址）的主机名称为prtsvr,要求自动分配固定IP地址为192.168.4.9
推荐步骤
确认服务器的网络地址设置正确
(1)修改网卡eth0的配置文件ifcfg-eth0，将IP地址设为192.168.4.11/24,默认网关地址设为192.168.4.1
[root@test1 Desktop]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
UUID=2a9f7302-e5a6-421a-bdc9-d386911222df
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=192.168.4.11
NETMASK=255.255.255.0
GATEWAY=192.168.4.1
~
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-- INSERT --
(2)修改主机名配置文件network，将主机名设为dhcpsvr.kgc.com.
[root@test1 Desktop]# vi /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=dhcpsvr.kgc.com
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Type :quit to exit Vim
重启
[root@dhcpsvr Desktop]# hostname
dhcpsvr.kgc.com
[root@dhcpsvr Desktop]#
(3)修改本地主机映射文件hosts,添加dhcpsvr,ns1,ns2,prtsvr这四台主机的IP地址映射记录,以提高主机查找效率.
[root@dhcpsvr Desktop]# vi /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.4.11 dhcpsvr.kgc.com
192.168.4.2 ns1.kgc.com
192.168.4.3 ns2.kgc.com
192.168.4.9 prtsvr
~
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~
:wq
(4)修改域名解析配置文件resolv.conf，添加两行配置记录，指定两台DNS服务器的 IP 地址分别为 192.168.4.2 和 192.168.4.3。
[root@dhcpsvr Desktop]# vi /etc/resolv.conf
# Generated by NetworkManager
search kgc.com
nameserver 192.168.4.2
nameserver 192.168.4.3
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
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:wq
(5)重新启动主机，以使修改的各种地址配置生效
安装并配置DHCP服务
(1)挂载 RHEL6 光盘，安装 dhcp-4.1.1-38.P1.el6.x86_64.rpm 软件包
[root@dhcpsvr Desktop]# rpm -qa | grep dhcp
dhcp-4.1.1-38.P1.el6.centos.x86_64
dhcp-common-4.1.1-38.P1.el6.centos.x86_64
[root@dhcpsvr Desktop]#
(2)编辑dhcpd.conf配置文件，根据题意要求添加 subnet声明,“option routers”与“option domain-name-servers”配置选项,range配置参数，添加host声明为prtsvr綁定固定IP地址，适当调整全局配置。
[root@Daring Desktop]# vi /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=prtsvr
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:wq
[root@Daring Desktop]# reboot
[root@dhcpsvr dhcp]# pwd
/etc/dhcp
[root@dhcpsvr dhcp]# vi dhcpd.conf
1 # dhcpd.conf
2 #
3 # Sample configuration file for ISC dhcpd
4 #
5
6
7 default-lease-time 21600;
8 max-lease-time 43200;
9 option domain-name "kgc.com";
10 option domain-name-servers 192.168.4.2, 192.168.4.3;
11
12 subnet 192.168.4.0 netmask 255.255.255.0 {
13 range 192.168.4.20 192.168.4.200;
14 option routers 192.168.4.1;
15 }
16
17 hot prtsvr {
18 hardware ehternet 00:0C:29:3B:AF:22;
19 fixed-address 192.168.4.9;
20 }
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:wq
(3)启动dhcpd服务,确认服务监听正常。
[root@dhcpsvr dhcp]# service dhcpd start
Starting dhcpd: [FAILED]
[root@dhcpsvr dhcp]# ls
dhclient.d dhcpd6.conf dhcpd.conf
[root@dhcpsvr dhcp]# vi dhcpd.conf
# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#
default-lease-time 21600;
max-lease-time 43200;
option domain-name "kgc.com";
option domain-name-servers 192.168.4.2, 192.168.4.3;
subnet 192.168.4.0 netmask 255.255.255.0 {
range 192.168.4.20 192.168.4.200;
option routers 192.168.4.1;
}
host prtsvr {
hardware ehternet 00:0C:29:3B:AF:22;
fixed-address 192.168.4.9;
}
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:wq
[root@dhcpsvr dhcp]# service dhcpd start
Starting dhcpd: [FAILED]
[root@dhcpsvr dhcp]# vi dhcpd.conf
# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#
default-lease-time 21600;
max-lease-time 43200;
option domain-name "kgc.com";
option domain-name-servers 192.168.4.2, 192.168.4.3;
subnet 192.168.4.0 netmask 255.255.255.0 {
range 192.168.4.20 192.168.4.200;
option routers 192.168.4.1;
host prtsvr {
hardware ehternet 00:0C:29:3B:AF:22;
fixed-address 192.168.4.9;
}
}
~
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:wq
[root@dhcpsvr dhcp]# vi dhcpd.conf
[root@dhcpsvr dhcp]# cat dhcpd.conf
# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#
# option definitions common to all supported networks...
option domain-name kgc.com;
option domain-name-servers 192.168.4.2, 192.168.4.3;
default-lease-time 600;
max-lease-time 7200;
# Use this to enble / disable dynamic dns updates globally.
ddns-update-style none;
# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;
# This is a very basic subnet declaration.
subnet 192.168.4.0 netmask 255.255.255.0 {
range 192.168.4.20 192.168.4.200;
option routers 192.168.4.1;
}
host prtsvr {
hardware ethernet 00:0C:29:3B:AF;22;
fixed-address 192.168.4.9;
}
[root@dhcpsvr dhcp]# service dhcpd start
Starting dhcpd: [FAILED]
[root@dhcpsvr dhcp]#
内核版本
[root@dhcpsvr home]# uname -r
3.10.0-327.el7.x86_64
查看hostname
[root@dhcpsvr home]# cat /etc/sysconfig/network
# Created by anaconda
HOSTNAME=dhcpsvr.kgc.com
查看hosts
[root@dhcpsvr home]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.4.11 dhcpsvr.kgc.com
192.168.4.2 ns1.kgc.com
192.168.4.3 ns2.kgc.com
192.168.4.9 prtsvr
查看网卡配置文件
[root@dhcpsvr home]# cat /etc/sysconfig/network-scripts/ifcfg-eno16777736
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_FAILURE_FATAL=no
NAME=eno16777736
UUID=5619b5f1-8c7b-4d53-b78f-f4160783dcf0
DEVICE=eno16777736
ONBOOT=yes
IPADDR=192.168.4.11
NETMASK=255.255.255.0
GATEWAY=192.168.4.1
查看dns配置
[root@dhcpsvr home]# cat /etc/resolv.conf
# Generated by NetworkManager
search kgc.com
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
重新设置dns
[root@dhcpsvr home]# vi /etc/resolv.conf
[root@dhcpsvr home]# cat /etc/resolv.conf
# Generated by NetworkManager
search kgc.com
nameserver 192.168.4.2
nameserver 192.168.4.3
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
[root@dhcpsvr home]#
查看/etc/dhcp/dhcpd.conf
>>测试DHCP自动获取地址
(1)在客户机中，将网卡设置为自动获取地址，验证是否成功。
```bash
[root@prtsvr Desktop]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=00:0C:29:3B:AF:22
TYPE=Ethernet
UUID=e8defc61-064f-44a5-8772-b1bf4cc3cec8
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=dhcp
IPADDR=192.168.0.103
GATEWAY=192.168.4.1
~
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:wq
(2)在网络打印机prtsvr中，验证是否能够成功获取保留的IP地址192.168.4.9
[root@prtsvr Desktop]# service network restart
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0:
Determining IP information for eth0... done.
[ OK ]
[root@prtsvr Desktop]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:3B:AF:22
inet addr:192.168.4.9 Bcast:192.168.4.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe3b:af22/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:32 errors:0 dropped:0 overruns:0 frame:0
TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5679 (5.5 KiB) TX bytes:2022 (1.9 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:164 errors:0 dropped:0 overruns:0 frame:0
TX packets:164 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11368 (11.1 KiB) TX bytes:11368 (11.1 KiB)
[root@prtsvr Desktop]#
网络打印机当中能够获取到指定的IP地址。
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_FAILURE_FATAL=no
NAME=eno16777736
UUID=18a130f9-c170-4d78-a03a-57761761a369
DEVICE=eno16777736
ONBOOT=yes
IPADDR=192.168.0.107
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:wq