Linux DNS 主从复制

设置主从DNS的主要是为了冗余，分担压力，防止服务器宕机后，DNS无法正常解析。

---

配置 master

正常配置DNS服务。

设置主机名

[root@localhost ~]# hostnamectl set-hostname master
[root@localhost ~]# bash

安装 bind 包

[root@master ~]# yum install bind bind-utils -y

编辑主配置文件

[root@master ~]# vim /etc/named.conf

• 配置监听网段、允许查询网段

listen-on port 53 { 192.168.28.128; };
allow-query     { any; };

编辑区域配置文件

[root@master ~]# vim /etc/named.rfc1912.zones

zone "yun.com" IN {
        type master;
        file "yun.com.zone";
        allow-update { none; };
};

zone "100.168.192.in-addr.arpa" IN {
        type master;
        file "100.168.192.zone";
        allow-update { none; };
};

编辑区域数据配置文件

[root@master ~]# cd /var/named/

• 编辑正向区域数据文件

[root@master named]# cp -p named.localhost yun.com.zone
[root@master named]# vim yun.com.zone
$TTL 1D
@	IN SOA	yun.com admin.yun.com. (
					0	; serial
					1D	; refresh
					1H	; retry
					1W	; expire
					3H )	; minimum
	IN	NS	yun.com.
	IN	A	192.168.28.128
	IN	MX 10	mail.yun.com.
www	IN	A	192.168.100.10
ftp	IN	A	192.168.100.20
bbs	IN	CNAME	www
*	IN	A	8.8.8.8

• 编辑反向区域数据文件

[root@master named]# cp -p yun.com.zone 100.168.192.zone
[root@master named]# vim 100.168.192.zone
$TTL 1D
@       IN SOA  yun.com admin.yun.com. (
                                        0       ; serial
                                        1D      ; refresh
                                        1H      ; retry
                                        1W      ; expire
                                        3H )    ; minimum
        IN      NS      yun.com.
        IN      A       192.168.28.128
10      IN      PTR     www.yun.com.
20      IN      PTR     ftp.yun.com.

启动服务

[root@master ~]# systemctl start named
[root@master ~]# systemctl enable named
Created symlink from /etc/systemd/system/multi-user.target.wants/named.service to /usr/lib/systemd/system/named.service.

[root@master ~]# netstat -ntuap | grep named
tcp        0      0 192.168.28.128:53       0.0.0.0:*               LISTEN      34822/named
tcp        0      0 127.0.0.1:953           0.0.0.0:*               LISTEN      34822/named
tcp6       0      0 ::1:53                  :::*                    LISTEN      34822/named
tcp6       0      0 ::1:953                 :::*                    LISTEN      34822/named
udp        0      0 192.168.28.128:53       0.0.0.0:*                           34822/named
udp6       0      0 ::1:53                  :::*                                34822/named

关闭防火墙

[root@master ~]# systemctl stop firewalld
[root@master ~]# setenforce 0

nslookup

• 设置DNS地址

[root@master ~]# vim /etc/resolv.conf
# Generated by NetworkManager
search localdomain
nameserver 192.168.28.128

• 正向查询

[root@master ~]# nslookup www.yun.com
Server:		192.168.28.128
Address:	192.168.28.128#53

Name:	www.yun.com
Address: 192.168.100.10

[root@master ~]# nslookup ftp.yun.com
Server:		192.168.28.128
Address:	192.168.28.128#53

Name:	ftp.yun.com
Address: 192.168.100.20

[root@master ~]# nslookup bbs.yun.com
Server:		192.168.28.128
Address:	192.168.28.128#53

bbs.yun.com	canonical name = www.yun.com.
Name:	www.yun.com
Address: 192.168.100.10

[root@master ~]# nslookup asd.yun.com
Server:		192.168.28.128
Address:	192.168.28.128#53

Name:	asd.yun.com
Address: 8.8.8.8

• 反向查询

[root@master ~]# nslookup 192.168.100.10
Server:		192.168.28.128
Address:	192.168.28.128#53

10.100.168.192.in-addr.arpa	name = www.yun.com.

[root@master ~]# nslookup 192.168.100.20
Server:		192.168.28.128
Address:	192.168.28.128#53

20.100.168.192.in-addr.arpa	name = ftp.yun.com.

allow-transfer

这是最重要的一步，允许传送。配置好后重启服务。

[root@master ~]# vim /etc/named.rfc1912.zones

zone "yun.com" IN {
        type master;
        file "yun.com.zone";
        allow-transfer { 192.168.28.129; };
        allow-update { none; };
};

zone "100.168.192.in-addr.arpa" IN {
        type master;
        file "100.168.192.zone";
        allow-transfer { 192.168.28.129; };
        allow-update { none; };
};

---

配置 slave

设置主机名

[root@localhost ~]# hostnamectl set-hostname slave
[root@localhost ~]# bash

安装 bind 包

[root@slave ~]# yum install bind bind-utils -y

编辑主配置文件

[root@slave ~]# vim /etc/named.conf

• 配置监听网段、允许查询网段

listen-on port 53 { 192.168.28.129; };
allow-query     { any; };

编辑区域配置文件

[root@slave ~]# vim /etc/named.rfc1912.zones

zone "yun.com" IN {
        type slave;
        file "slaves/yun.com.zone";
        masters { 192.168.28.128; };
        allow-update { none; };
};

zone "100.168.192.in-addr.arpa" IN {
        type slave;
        file "slaves/100.168.192.zone";
        masters { 192.168.28.128; };
        allow-update { none; };
};

启动服务

[root@slave ~]# systemctl start named
[root@slave ~]# systemctl enable named
Created symlink from /etc/systemd/system/multi-user.target.wants/named.service to /usr/lib/systemd/system/named.service.

[root@slave ~]# netstat -ntuap | grep named
tcp        0      0 192.168.28.129:53       0.0.0.0:*               LISTEN      1661/named
tcp        0      0 127.0.0.1:953           0.0.0.0:*               LISTEN      1661/named
tcp6       0      0 ::1:53                  :::*                    LISTEN      1661/named
tcp6       0      0 ::1:953                 :::*                    LISTEN      1661/named
udp        0      0 192.168.28.129:53       0.0.0.0:*                           1661/named
udp6       0      0 ::1:53                  :::*                                1661/named

关闭防火墙

[root@slave ~]# systemctl stop firewalld
[root@slave ~]# setenforce 0

• 区域数据文件自动传送到从服务器

[root@slave ~]# ll /var/named/slaves/
total 8
-rw-r--r--. 1 named named 378 Sep 12 02:11 100.168.192.zone
-rw-r--r--. 1 named named 392 Sep 12 02:11 yun.com.zone

nslookup

• 设置DNS地址

[root@slave ~]# vim /etc/resolv.conf
# Generated by NetworkManager
search localdomain
nameserver 192.168.28.129

• 正向查询

[root@slave ~]# nslookup www.yun.com
Server:		192.168.28.129
Address:	192.168.28.129#53

Name:	www.yun.com
Address: 192.168.100.10

[root@slave ~]# nslookup ftp.yun.com
Server:		192.168.28.129
Address:	192.168.28.129#53

Name:	ftp.yun.com
Address: 192.168.100.20

[root@slave ~]# nslookup bbs.yun.com
Server:		192.168.28.129
Address:	192.168.28.129#53

bbs.yun.com	canonical name = www.yun.com.
Name:	www.yun.com
Address: 192.168.100.10

[root@slave ~]# nslookup asd.yun.com
Server:		192.168.28.129
Address:	192.168.28.129#53

Name:	asd.yun.com
Address: 8.8.8.8

• 反向查询

[root@slave ~]# nslookup 192.168.100.10
Server:		192.168.28.129
Address:	192.168.28.129#53

10.100.168.192.in-addr.arpa	name = www.yun.com.

[root@slave ~]# nslookup 192.168.100.20
Server:		192.168.28.129
Address:	192.168.28.129#53

20.100.168.192.in-addr.arpa	name = ftp.yun.com.