Linux中DDNS配置

1、实验拓扑结构

图1 实验拓扑图

2、项目要求

通过系统的搭建，能够为Web Server动态更新DNS信息。

3、项目开展思路（思维导图）

图2 DDNS实验思维导图

4、实验步骤

(1) 基础网络搭建

DHCP Server能Ping通DNS Server

图3 网络连通测试

(2)在DNS Server上

1)安装DNS服务

[root@lyy 桌面]# yum install bind -y

2)生成密钥

[root@lyy 桌面]# mkdir key

[root@lyy 桌面]# cd key/

[root@lyy key]# dnssec-keygen -a HMAC-MD5 -b 512 -n HOST www

Kwww.+157+55680

[root@lyy key]# ls

Kwww.+157+55680.key Kwww.+157+55680.private

[root@lyy key]# cat Kwww.+157+55680.key

www. IN KEY 512 3 157 7mThflorkZ+uJGSGK7XmKxYkDxm+nzP49CITZ+njEmQajyAWkk8lTtpw 8AnC+pMP8hXGu2QK5hf4zlaqf4DzSw==

3)配置主配置文件named.conf

将生成的公钥（空格去掉）复制到named.conf中，加入key字段

options {

listen-on port 53 { any; };

directory "/var/named";

dump-file "/var/named/data/cache_dump.db";

statistics-file "/var/named/data/named_stats.txt";

memstatistics-file "/var/named/data/named_mem_stats.txt";

allow-query { any; };

};

key www {

algorithm hmac-md5;

secret"7mThflorkZ+uJGSGK7XmKxYkDxm+nzP49CITZ+njEmQajyAWkk8lTtpw8AnC+pMP8hXGu2QK5hf4zlaqf4DzSw==";

};

zone "xh27.com" IN {

type master;

file "named.xh27.com";

allow-update {

key www;

};

zone "0.168.192.in-addr.arpa" IN {

type master;

file "named.192.168.0";

allow-update {

key www;

};

4)添加正解文件

[root@lyy 桌面]# cd /var/named/

[root@lyy named]# touch named.xh27.com

[root@lyy named]# gedit named.xh27.com

$TTL 3H

@ IN SOA master.xh27.com. admin.mail.xh27.com. (

0 ; serial

1D ; refresh

1H ; retry

1W ; expire

3H ) ; minimum

@ IN NS master.xh27.com.

master.xh27.com. IN A 192.168.0.253

5)添加反解文件

[root@lyy named]# touch named.192.168.0

[root@lyy named]# gedit named.192.168.0

$TTL 3H

@ IN SOA master.xh27.com. admin.mail.xh27.com. (

0 ; serial

1D ; refresh

1H ; retry

1W ; expire

3H ) ; minimum

@ IN NS master. xh27.com.

253 IN PTR master. xh27.com.

6)防火墙开放53端口

[root@lyy named]# iptables -I INPUT -i eth0 -p udp --dport 53 -j ACCEPT

[root@lyy named]# iptables -I INPUT -i eth0 -p tcp --dport 53 -j ACCEPT

7)设置Selinux

[root@lyy named]# setsebool -P named_write_master_zones=1

//允许动态更新文件的写入

8)设置文件夹权限

[root@lyy named]# chmod g+w /var/named

[root@lyy named]# chown named /var/named

9)启动DNS服务

[root@lyy named]# service named start

(3)在DHCP Server上

1)安装DHCP服务

[root@lyy yum.repos.d]# yum install dhcp -y

2)配置DHCP主配置文件

[root@lyy yum.repos.d]# gedit /etc/dhcp/dhcpd.conf

option domain-name "xh27.com";

option domain-name-servers master.xh27.com;

default-lease-time 600;

max-lease-time 7200;

ddns-update-style interim;

key www {

algorithm hmac-md5; secret"7mThflorkZ+uJGSGK7XmKxYkDxm+nzP49CITZ+njEmQajyAWkk8lTtpw8AnC+pMP8hXGu2QK5hf4zlaqf4DzSw==";

}

zone xh27.com {

key www;

primary 192.168.0.253;

}

zone 0.168.192.in-addr.arpa {

key www;

primary 192.168.0.253;

}

subnet 192.168.0.0 netmask 255.255.255.0 {

range 192.168.0.50 192.168.0.150;

option routers 192.168.0.254;

}

3)设置DNS服务器

[root@lyy yum.repos.d]# gedit /etc/resolv.conf

nameserver 192.168.0.253

4)启动DHCP服务

[root@lyy yum.repos.d]# service dhcpd start

(4)在WEB server上

1)设置主机名

[root@lyy 桌面]# gedit /etc/sysconfig/network

HOSTNAME=www

2)重启网络服务

[root@www 桌面]# service network restart

[root@www 桌面]# ifconfig

图4 WEB Server第一次获取IP

5、结果检测

（1)在DHCP Server上

将IP地址分配的范围从50-150，改为151-200，重启DHCP服务器

图5 修改分配的IP范围

[root@lyy yum.repos.d]# service dhcpd restart

（2)在WEB Server上

1)重启网络服务

图6 WEB Server第二次获取IP

2)解析www.xh27.com和192.168.0.151

图7 WEB Server解析域名和IP

（3)在DNS Server上

1)查看获取的动态更新文件

[root@lyy 桌面]# ll /var/named/

图 8 DNS查看更新文件

2)查看日志文件

[root@lyy 桌面]# gedit /var/log/messages

图 9 DNS查看日志文件