DNS (Domain Name Server)域名解析系统详解

原理解析：
网络中为了区别各个主机，必须为每台主机分配一个惟一的地址，这个地址即称为“IP地址”。但这些数字难以记忆，所以就采用“域名”的方式来取代这些数字了。

企业应用：
DNS服务一般除了服务提供商（如：电信）以外，一般企业只是用于辅助性的解析自己内部网络的主机IP，当外部网络解析不了时，需要做DNS转发至服务提供商。

1,################

rpm -ivh   bind-9.3.3-7.e15.i386.rpm---------->  2
           caching-namerserver-------------->    4

2,################

vi /etc/named.caching-nameserver.conf

options {
        listen-on port 53 { 192.168.1.2; };
//      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"
        query-source    port 53;
//      query-source-v6 port 53;
        allow-query     { any; };
 forward only;                 #做DNS转发
 forwarders {61.147.37.1;};
};
logging {
        channel default_debug {
                file "data/named.run"
                severity dynamic;
        };
};
view localhost_resolver {
//      match-clients      { localhost; };
//      match-destinations { localhost; };
        recursion yes;
        include "/etc/named.rfc1912.zones"
};

3.################

vi /etc/named.rfc1912.zones

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

zone "1.168.192.in-addr.arpa" IN {
        type master;
        file "qianluo.local"
        allow-update { none; };
};

4.################

cp -rf /var/named/named.zone /var/named/qianluo.zone
cp -rf /var/named/named.local /var/named/qianluo.local

5.################

chown named.named /var/named/qianluo.zone
chown named.named /var/named/qianluo.local

6.################

vi /var/named/qianluo.zone
$TTL    86400
@               IN SOA  qianluo.com.       root.qianluo.com. (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum

                IN NS           ns1. qianluo.com.
                IN A            192.168.1.2
ns1             IN      A       192.168.1.2
www             IN      A       61.123.1.1

7.###############

vi /var/named/qianluo.local

$TTL    86400
@       IN      SOA     qianluo.com. root.qianluo.com.  (
                                      1997022700 ; Serial
                                      28800      ; Refresh
                                      14400      ; Retry
                                      3600000    ; Expire
                                      86400 )    ; Minimum
        IN      NS      ns1.qianluo.com.
2       IN      PTR     qianluo.com.
2       IN      PTR     ftp.qianluo.com.

8.
   vi /etc/resolv.conf
     nameserver 192.168.1.2

9.
iptables -F
iptables -t nat -F
service network restart
service named restart

10.################

host www.qianluo.com
host 192.168.1.2

11.################

tail /var/log/messages