1. BIND的区域传送(主从同步)

当一个域内主DNS宕机或者压力过高时就需要在添加一台DNS服务器用来顶替主DNS或者缓解主DNS的压力。

主机规划：

3.1 配置区域传送的步骤

向区域中添加从服务器的关键两步步：

(在上级获得授权)

在区域数据文件中为从服务器添加一条NS记录和对应的A记录；

3.2 安装从DNS服务器

[root@dns_slave ~]# yum -y  install bind
[root@dns_slave ~]# mv /etc/named.conf/etc/named.conf.ori
[root@dns_slave ~]# vim /etc/named.conf
options {directory "/var/named/";
};
zone "." IN {type hint;file "named.ca";
};
zone "localhost" IN {type master;file "named.localhost";
};
zone "1.0.0.127.in-addr.arpa"IN {type master;file "named.loopback";
};
zone "enzhi.com." IN {type slave;masters { 192.168.233.135; };file "slaves/enzhi.com.zone";
};
zone"233.168.192.in-addr.arpa" IN {type slave;masters { 192.168.233.135; };file "slaves/192.168.233.zone";
};

#masters { DNS_SERVER_IP； }; 指定主DNS服务器IP地址

注意：

#从服务器的区域数据文件不需要自己创建，从服务器会自动的从主服务器上复制到从服务器中的/var/named/slaves/目录下。所以从服务器的区域配置文件中file的路径要写相对路径file"slaves/enzhi.com.zone";

3.3 配置主服务器主配置文件授权从服务器

#在主服务器的zone中添加一行allow-transfer{ SLAVE_SERVER_IP;}；允许某个从服务器可以复制区域数据文件。

[root@dns_master named]# vi  /etc/named.conf
options {directory "/var/named";
};
zone "." IN {type hint;file "named.ca";
};
zone "localhost" IN {type master;file "named.localhost";
};
zone "1.0.0.127.in-addr.apra"IN {type master;file "named.loopback";
};
zone "enzhi.com." IN {type master;file "enzhi.com.zone";allow-transfer { 192.168.233.134; };
};
zone"233.168.192.in-addr.arpa" IN {type master;file "192.168.233.zone";allow-transfer { 192.168.233.134; };
};

3.4修改主服务器的区域文件添加从服务器的ns记录

[root@dns_master named]# vimenzhi.com.zone
$TTL 600
@      IN      SOA     ns.enzhi.com.   admin.enzhi.com. (20160324012H5M7D1D )IN      NS      nsIN      NS      ns2IN      MX  10 mail
ns     IN      A       192.168.233.135
ns2     IN     A       192.168.233.134
mail   IN      A       192.168.233.11
www    IN      A       192.168.233.10
ftp    IN      CNAME   www

#修改反向区域数据文件

[root@dns_master named]# vim 192.168.233.zone
$TTL 600
@      IN      SOA     ns.enzhi.com.   admin.enzhi.com. (20160324012H5M7D1D )@      IN      NS      ns.enzhi.com.IN     NS      ns2.enzhi.com.
135    IN      PTR     ns.enzhi.com.
134     IN     PTR     ns2.enzhi.com.
11     IN      PTR     mail.enzhi.com.
10     IN      PTR     www.enzhi.com.

#语法检查并重启nsmed服务

[root@dns_master named]# named-checkzone"233.168.192.in-addr.arpa" 192.168.233.zone
zone 233.168.192.in-addr.arpa/IN: loadedserial 2016032401
OK
[root@dns_master named]#/etc/init.d/named reload
Reloading named:                     [ OK  ]

3.5 启动dns-slave的named服务

[root@dns_slave ~]# /etc/init.d/namedconfigtest  #语法检查
zone localhost/IN: loaded serial 0
zone 1.0.0.127.in-addr.arpa/IN: loadedserial 0
[root@dns_slave ~]# /etc/init.d/namedstart         #启动named
Generating /etc/rndc.key:                  [  OK  ]
Starting named:                       [  OK  ]
#检查区域数据文件是否成功复制过来
[root@dns_slave ~]# cd/var/named/slaves/
[root@dns_slave slaves]# ls
192.168.233.zone  enzhi.com.zone

3.6 使用dig命令测试slave能否解析

[root@dns_slave slaves]# dig -t A www.enzhi.com @192.168.233.134; <<>> DiG9.8.2rc1-RedHat-9.8.2-0.37.rc1.el6_7.7 <<>> -t A www.enzhi.com@192.168.233.134
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode:QUERY, status: NOERROR, id: 15935
;; flags: qr aa rd ra; QUERY: 1, ANSWER:1, AUTHORITY: 2, ADDITIONAL: 2;; QUESTION SECTION:
;www.enzhi.com.                 IN      A;; ANSWER SECTION:
www.enzhi.com.          600     IN     A       192.168.233.10;; AUTHORITY SECTION:
enzhi.com.              600    IN      NS      ns2.enzhi.com.
enzhi.com.              600     IN     NS      ns.enzhi.com.;; ADDITIONAL SECTION:
ns.enzhi.com.           600     IN     A       192.168.233.135
ns2.enzhi.com.          600     IN     A       192.168.233.134;; Query time: 1 msec
;; SERVER:192.168.233.134#53(192.168.233.134)
;; WHEN: Thu Mar 24 12:43:39 2016
;; MSG SIZE  rcvd: 114

#反向解析

[root@dns_slave slaves]# dig -x192.168.233.10 @192.168.233.134; <<>> DiG9.8.2rc1-RedHat-9.8.2-0.37.rc1.el6_7.7 <<>> -x 192.168.233.10@192.168.233.134
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode:QUERY, status: NOERROR, id: 28690
;; flags: qr aa rd ra; QUERY: 1, ANSWER:1, AUTHORITY: 2, ADDITIONAL: 2;; QUESTION SECTION:
;10.233.168.192.in-addr.arpa.   IN     PTR;; ANSWER SECTION:
10.233.168.192.in-addr.arpa. 600 IN     PTR    www.enzhi.com.;; AUTHORITY SECTION:
233.168.192.in-addr.arpa. 600   IN     NS      ns2.enzhi.com.
233.168.192.in-addr.arpa. 600   IN     NS      ns.enzhi.com.;; ADDITIONAL SECTION:
ns.enzhi.com.           600     IN     A       192.168.233.135
ns2.enzhi.com.          600     IN     A       192.168.233.134;; Query time: 1 msec
;; SERVER:192.168.233.134#53(192.168.233.134)
;; WHEN: Thu Mar 24 12:44:58 2016
;; MSG SIZE  rcvd: 139