如何搭建智能DNS系统？

搭建智能DNS需配置ACL、view和区域文件，以实现不同区域用户访问就近服务器。

智能DNS搭建指南

一、环境准备

1、硬件要求：

至少需要一台服务器，具备稳定的网络连接。

若需高可用性，可配置多台服务器作为主从服务器。

2、软件要求：

操作系统：Linux（如CentOS、Ubuntu等）。

DNS服务器软件：Bind9或SmartDNS。

二、DNS服务器网卡配置

假设使用两台虚拟机，分别模拟北京和上海的服务器。

北京服务器IP配置：

ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:95:87:a5 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.146/24 brd 10.0.0.255 scope global dynamic noprefixroute eth0
       valid_lft 1310sec preferred_lft 1310sec
    inet6 fe80::7dd4:5200:f267:e9cd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:95:87:af brd ff:ff:ff:ff:ff:ff
    inet 172.16.0.8/16 brd 172.16.255.255 scope global noprefixroute eth1
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe95:87af/64 scope link 
       valid_lft forever preferred_lft forever

上海服务器IP配置：

ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:95:87:a5 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.147/24 brd 10.0.0.255 scope global dynamic noprefixroute eth0
       valid_lft 1310sec preferred_lft 1310sec
    inet6 fe80::7dd4:5200:f267:e9cd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:95:87:af brd ff:ff:ff:ff:ff:ff
    inet 172.16.0.7/16 brd 172.16.255.255 scope global noprefixroute eth1
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe95:87af/64 scope link 
       valid_lft forever preferred_lft forever

三、DNS服务端配置文件实现View

安装Bind9并进行基本配置：

sudo aptget update
sudo aptget install bind9 y

编辑/etc/bind/named.conf.local文件：

options {
    directory "/var/cache/bind";
    recursion yes;
    allowquery { any; };
    allowtransfer { none; };
};
acl beijingnet {
    10.0.0.0/24;
};
acl shanghainet {
    172.16.0.0/16;
};
acl othernet {
    any;
};
view "beijingview" {
    matchclients { beijingnet; };
    include "/etc/bind/named.rfc1912.zones.bj";
};
view "shanghaiview" {
    matchclients { shanghainet; };
    include "/etc/bind/named.rfc1912.zones.sh";
};
view "otherview" {
    matchclients { othernet; };
    include "/etc/bind/named.rfc1912.zones.other";
};
include "/etc/bind/named.root.key";

四、实现区域配置文件

创建并编辑区域配置文件：

sudo nano /etc/bind/named.rfc1912.zones.bj
zone "." IN {
        type hint;
        file "named.ca";
};                                                                                                                                    
zone "jiangfeng.org" {
        type master;
        file "jiangfeng.org.zone.bj";
};

sudo nano /etc/bind/named.rfc1912.zones.sh
zone "." IN {
        type hint;
        file "named.ca";
};
zone "jiangfeng.org" {
        type master;
        file "jiangfeng.org.zone.shang";
};

sudo nano /etc/bind/named.rfc1912.zones.other
zone "." IN {
        type hint;
        file "named.ca";
};
zone "jiangfeng.org" {
        type master;
        file "jiangfeng.org.zone.other";

五、创建区域数据库文件

根据不同区域创建相应的数据库文件：

sudo nano /var/named/jiangfeng.org.zone.bj
$TTL    86400
@       IN      SOA     ns1.jiangfeng.org. admin.jiangfeng.org. (
                             2         ; Serial
                           7200      ; Refresh
                            1209600   ; Retry
                           1814400   ; Expire
                            86400 )   ; Negative Cache TTL
);
@       IN      NS      ns1.jiangfeng.org.
@       IN      A       192.168.1.1
www     IN      A       192.168.1.10
ftp     IN      A       192.168.1.11
mail    IN      A       192.168.1.12

sudo nano /var/named/jiangfeng.org.zone.shang
$TTL    86400
@       IN      SOA     ns1.jiangfeng.org. admin.jiangfeng.org. (
                             2         ; Serial
                           7200      ; Refresh
                            1209600   ; Retry
                           1814400   ; Expire
                            86400 )   ; Negative Cache TTL
);
@       IN      NS      ns1.jiangfeng.org.
@       IN      A       192.168.2.1
www     IN      A       192.168.2.10
ftp     IN      A       192.168.2.11
mail    IN      A       192.168.2.12

sudo nano /var/named/jiangfeng.org.zone.other
$TTL    86400
@       IN      SOA     ns1.jiangfeng.org. admin.jiangfeng.org. (
                             2         ; Serial
                           7200      ; Refresh
                            1209600   ; Retry
                           1814400   ; Expire
                            86400 )   ; Negative Cache TTL
);
@       IN      NS      ns1.jiangfeng.org.
@       IN      A       192.168.3.1
www     IN      A       192.168.3.10
ftp     IN      A       192.168.3.11
mail    IN      A       192.168.3.12

完成以上步骤后，重新启动Bind9服务：