智能DNS

一、智能多区域DNS测试环境说明：

主DNS:175.22.3.90 从DNS:175.22.3.91 缓存DNS：175.22.3.92 测试域名：bctest.com 区域：

Foshan机房:

www.bctest.com 59.38.124.123 nstest.bctest.com 59.38.124.123

yangzhou机房：www.bctest.com 61.147.118.202

nstest.bctest.com 61.147.118.202

Zhengzhou机房： www.bctest.com 61.158.247.5 nstest.bctest.com 61.158.247.5

any其他：www.bctest.com 121.14.46.232 nstest.bctest.com 121.14.46.232 测试系统：CentOs 5.4

测试软件：bind-9.3.6-4.P1.el5.i386.rpm

caching-nameserver-9.3.6-4.P1.el5.i386.rpm

二、搭建智能多区域主DNS服务器

1，安装bind-9.3、caching-nameserver-9.3.6软件

rpm -ivh bind-9.3.6-4.P1.el5.i386.rpm

rpm -ivh caching-nameserver-9.3.6-4.P1.el5.i386.rpm

2，修改/etc/named.conf主配置文件:

[root@localhost ~]#Cat /etc/named.conf

==============================start named.conf =============================== options { listen-on port 53 { any; };

listen-on-v6 port 53 { ::1; };

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\"; }; logging {

channel default_debug {

file \"data/named.run\"; severity dynamic; };

};

include \"foshan_acl.conf\"; include \"yangzhou_acl.conf\"; include \"zhengzhou_acl.conf\"; view \"view_foshan\" { match-clients { FOSHAN; };

zone \".\" {

type hint;

file \"named.ca\"; };

include \"master/foshan.def\"; };

view \"view_yangzhou\" { match-clients { YANGZHOU; };

zone \".\" {

type hint; file \"named.ca\"; };

include \"master/yangzhou.def\"; };

view \"view_zhengzhou\" { match-clients {

ZHENGZHOU; };

query-source port 53; query-source-v6 port 53; allow-query { any; };

zone \".\" {

type hint;

file \"named.ca\"; };

include \"master/zhengzhou.def\"; };

view \"view_any\" { match-clients { ANY; }; zone \".\" { type hint; file \"named.ca\"; };

include \"master/any.def\"; };

===============================end named.conf==============================

3，创建区域控制列表文件

[root@localhost ~]#Cat /var/named/foshan_acl.conf

============================start foshan_acl.conf============================= acl \"FOSHAN\" { 61.142.250.0/24; 59.38.124.0/24;

};

============================end foshan_acl.conf==============================

[root@localhost ~]#Cat /var/named/yangzhou_acl.conf

==========================start yangzhou _acl.conf============================= acl \"YANGZHOU\" { 61.147.118.0/24; 61.147.127.0/24; };

=========================end yangzhou _acl.conf==============================

[root@localhost ~]#Cat /var/named/zhengzhou_acl.conf

=========================start zhengzhou _acl.conf============================= acl \"ZHENGZHOU\" { 61.158.247.0/24; 61.158.244.0/24; 175.22.3.0/24; };

=========================end zhengzhou _acl.conf==============================

4，建立各区域解析配置文件

[root@localhost ~]#cat /var/named/master/foshan.def

============================start foshan_acl.conf============================= zone \"bctest.com\" { type master; };

file \"master/foshan/bctest.com\"; allow-transfer { 175.22.3.91; };

============================end foshan_acl.conf==============================

[root@localhost ~]#cat /var/named/master/yangzhou.def

=========================start yangzhou_acl.conf============================= zone \"bctest.com\" { type master;

file \"master/yangzhou/bctest.com\"; allow-transfer { 175.22.3.91; };

};

========================end yangzhou_acl.conf==============================

[root@localhost ~]#cat /var/named/master/zhengzhou.def

========================start zhengzhou_acl.conf============================= zone \"bctest.com\" {

type master;

file \"master/zhengzhou/bctest.com\"; allow-transfer { 175.22.3.91; };

};

========================end zhengzhou_acl.conf==============================

[root@localhost ~]#cat /var/named/master/any.def

============================start any_acl.conf============================= zone \"bctest.com\" { type master; file \"master/any/bctest.com\";

allow-transfer { 175.22.3.91; };

};

============================end any_acl.conf==============================

5，增加域名定义文件

[root@localhost ~]#cat /var/named/master/foshan/bctest.com

============================start any _acl.conf============================= $TTL 3600

$ORIGIN bctest.com.

@ IN SOA bctest.com. root.bctest.com. (

2011081701 ;Serial

3600 ;Refresh ( seconds ) 900 ;Retry ( seconds )

68400 ;Expire ( seconds )

15 ;Minimum TTL for Zone ( seconds ) ) nstest www ;

IN NS bctest.com. IN A 59.38.124.123 IN A 59.38.124.123

;end

============================end any _acl.conf==============================

[root@localhost ~]#cat /var/named/master/yangzhou/bctest.com

=========================start yangzhou _acl.conf============================= $TTL 3600

$ORIGIN bctest.com.

@ IN SOA bctest.com. root.bctest.com. (

2011081701 ;Serial 3600 ;Refresh ( seconds ) 900 ;Retry ( seconds ) 68400 ;Expire ( seconds )

15 ;Minimum TTL for Zone ( seconds ) ) nstest

IN NS bctest.com. IN A 61.147.118.202

www IN A 61.147.118.202 ; ;end

=========================end yangzhou _acl.conf==============================

[root@localhost ~]#cat /var/named/master/zhengzhou/bctest.com

=========================start zhengzhou _acl.conf============================= $TTL 3600

$ORIGIN bctest.com.

@ IN SOA bctest.com. root.bctest.com. (

2011081701 ;Serial

3600 ;Refresh ( seconds ) 900 ;Retry ( seconds )

68400 ;Expire ( seconds )

15 ;Minimum TTL for Zone ( seconds ) ) IN NS bctest.com. nstest www ; ;end

=========================end zhengzhou _acl.conf==============================

[root@localhost ~]#cat /var/named/master/any/bctest.com

============================start any _acl.conf============================= $TTL 3600

$ORIGIN bctest.com.

@ IN SOA bctest.com. root.bctest.com. (

2011081701 ;Serial 3600 ;Refresh ( seconds ) 900 ;Retry ( seconds )

68400 ;Expire ( seconds )

15 ;Minimum TTL for Zone ( seconds ) ) IN NS bctest.com. nstest www

IN A 121.14.46.232 IN A 121.14.46.232

IN A 61.158.247.5 IN A 61.158.247.5

; ;end

============================end any _acl.conf==============================

6，修改各目录的权限

[root@localhost ~]#chown –R named:named /var/named [root@localhost ~]#chown –R named:named /etc/named.*

7，启动dns服务

[root@localhost ~]#service named start 至此智能多区域主DNS已经完成配置

三、搭建智能多区域从DNS服务器

从DNS搭建起来相对主DNS要简单很多，从DNS服务器不需要建立自己的域名定义文件，它会自动从主DNS服务器上同步过来。下面我们来看看从DNS服务器的搭建：

1，安装DNS软件，和主服务器搭建一样，请参照主DNS服务器安

装步骤，此处省略。

2，修改/etc/named.conf主配置文件

[root@localhost ~]#Cat /etc/named.conf

============================start named .conf=============================

options {

listen-on port 53 { any; }; listen-on-v6 port 53 { ::1; }; directory dump-file

\"/var/named\";

\"/var/named/data/cache_dump.db\";

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

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

query-source port 53; query-source-v6 port 53;

allow-query { any; };

};

logging {

channel default_debug {

file \"data/named.run\"; severity dynamic; };

};

include \"foshan_acl.conf\"; include \"yangzhou_acl.conf\"; include \"zhengzhou_acl.conf\"; view \"view_foshan\" { match-clients { FOSHAN; };

zone \".\" {

type hint; file \"named.ca\"; };

include \"slaves/foshan.def\"; };

view \"view_yangzhou\" { match-clients { YANGZHOU; }; zone \".\" { type hint; file \"named.ca\"; };

include \"slaves/yangzhou.def\"; };

view \"view_zhengzhou\" { match-clients {

ZHENGZHOU; };

zone \".\" {

type hint;

file \"named.ca\"; };

include \"slaves/zhengzhou.def\"; };

view \"view_any\" { match-clients { ANY; };

zone \".\" {

type hint;

file \"named.ca\"; };

include \"slaves/any.def\";

};

============================end named .conf=============================

3，创建区域控制列表文件

[root@localhost ~]#Cat /var/named/foshan_acl.conf

============================start foshan_acl.conf============================= acl \"FOSHAN\" { 61.142.250.0/24;

59.38.124.0/24;

};

============================end foshan_acl.conf==============================

[root@localhost ~]#Cat /var/named/yangzhou_acl.conf

==========================start yangzhou _acl.conf============================= acl \"YANGZHOU\" { 61.147.118.0/24; 61.147.127.0/24; };

=========================end yangzhou _acl.conf==============================

[root@localhost ~]#Cat /var/named/zhengzhou_acl.conf

=========================start zhengzhou _acl.conf============================= acl \"ZHENGZHOU\" { 61.158.247.0/24; 61.158.244.0/24; 175.22.3.0/24; };

=========================end zhengzhou _acl.conf==============================

4，建立各区域解析配置文件

[root@localhost ~]#cat /var/named/slaves/foshan.def

============================start foshan_acl.conf============================= zone \"bctest.com\" {

type slave;

file \"slaves/foshan/bctest.com\"; masters{ 175.22.3.90; };

};

============================end foshan_acl.conf==============================

[root@localhost ~]#cat /var/named/slaves/yangzhou.def

=========================start yangzhou _acl.conf============================= zone \"bctest.com\" { type slave; file \"slaves/yangzhou/bctest.com\";

masters { 175.22.3.90; };

};

========================end yangzhou _acl.conf==============================

[root@localhost ~]#cat /var/named/slaves/zhengzhou.def

========================start zhengzhou _acl.conf============================= zone \"bctest.com\" { type slave; file \"slaves/zhengzhou/bctest.com\"; };

masters { 175.22.3.90; };

========================end zhengzhou _acl.conf==============================

[root@localhost ~]#cat /var/named/slaves/any.def

============================start any _acl.conf============================= zone \"bctest.com\" { };

type slave;

file \"slaves/any/bctest.com\"; masters { 175.22.3.90; };

============================end any _acl.conf==============================

5，创建各区域目录

[root@localhost ~]#mkdir /var/namd/slaves/foshan [root@localhost ~]#mkdir /var/namd/slaves/yangzhou [root@localhost ~]#mkdir /var/namd/slaves/zhengzhou [root@localhost ~]#mkdir /var/namd/slaves/any

6，修改各目录的权限

[root@localhost ~]#chown –R named:named /var/named [root@localhost ~]#chown –R named:named /etc/named.*

7，启动DNS服务

[root@localhost ~]#service named start

稍等几秒中后，我们可以去查看下域名定义文件是否从主DNS那边同步过来，

[root@localhost ~]#ls /var/name/slaves/foshan

至此从DNS服务器搭建完成。

四、搭建DNS高速缓存服务器

高速缓存DNS服务器搭建起来比从DNS服务器更为简单，高速缓存DNS服务器没有自己的区域解析配置文件及域名定义文件，它只有简单的转发功能，即紧紧做转发用。下面我们来看看高速缓存DNS服务器的搭建步骤：

1， 安装DNS软件，和主、从服务器搭建一样，请参照主DNS服

务器安装步骤，此处省略。

2，修改/etc/named.conf主配置文件

[root@localhost ~]#cat /etc/named.conf options {

listen-on port 53 { any; }; listen-on-v6 port 53 { ::1; }; directory dump-file

\"/var/named\";

\"/var/named/data/cache_dump.db\";

============================start named.conf =============================

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

memstatistics-file \"/var/named/data/named_mem_stats.txt\"; forward only; Forwarders {

175.22.3.90; 175.22.3.91; };

query-source port 53; query-source-v6 port 53;

allow-query { any; }; allow-query-cache { any; }; };

logging {

channel default_debug { file \"data/named.run\"; severity dynamic; }; };

============================end named.conf ==============================

3，修改目录权限

[root@localhost ~]#chown –R named:named /var/named [root@localhost ~]#chown –R named:named /etc/named.*

4，启动DNS服务

[root@localhost ~]#service named start

至此高速缓存DNS服务器已经搭建完成，简单吧^_^。

五、总结

智能DNS即通过DNS View配置，自动根据客户端IP来判断用户所处的网络,它可以让网通的用户解析出网通的IP,电信的解析出电信IP，使用户能够访问到临近的同网的服务器，避免跨网访问，从而提高访问速度，解决跨网互访带来网络延时过大问题。本次测试智能DNS是根据地区来指定解析，实验拓扑如下：

缓存DNS 用户 广州缓存 DNS 扬州缓存 DNS 北京 主DNS 天津 从DNS 郑州缓存 DNS