DNS大纲-DNS转发

配置：
 
外网DNS(真正提供解析的DNS):
 
#vim /etc/named.rfc1912.zones
zone "baidu.com" IN {
        type master;
        file "baidu.com.zx";
        allow-update { none; };
        allow-transfer { 202.103.24.88; };
};
:wq
# vim /var/named/baidu.com.zx
$TTL 3H
@       IN SOA  dns1.baidu.com. 1771079313.qq.com. (
                                        20180101        ; serial
                                        1D      ; refresh
                                        1H      ; retry
                                        1W      ; expire
                                        3H )    ; minimum
        NS      dns1.baidu.com.
dns1    A       202.103.24.11
www   A       192.168.1.76
mail    A       2.2.2.2
linux   A       3.3.3.3
 
:wq

# systemctl restart named
然后解析下服务是否正常
----------------
 
配置DNS转发器：
vim /etc/named.conf
     options {
         forwarders { 202.104.24.11; };   #真正的dns服务器的IP，把请求转发给谁
   };
:wq
 
# systemctl restart named
 
---------------
客户端：
配置网卡里面添加：
DNS1=192.168.1.73
:wq
# nslookup www.baidu.com
 
 
 
----------------------------
 
 
缓存软件：nscd.x86_64
 
解析
DNS清除缓存命令：rndc flush