1:安装DNS服务
   yum install bind -y
   
2:修改/etc/named.conf 配置文件
    listen-on port 53 { any; };
    listen-on-v6 port 53 { any; };
 
    allow-query     { any; };
	allow-query-cache   { any; };
#添加的正向解析
zone "b.com" IN {
    type master;
    file "b.com.zone";
    allow-transfer { none;};
allow-transfer { any; }    #允许转发
};
3:在/var/name/目录下添加一个文件:
vi b.com.zone
$TTL 1D
@   IN SOA  b.com. root (
                        42  ; serial
                        1D  ; refresh
                        1H  ; retry
                        1W  ; expire
                        3H )    ; minimum
    NS  @
    A   127.0.0.1
    AAAA    ::1
www IN A 172.30.7.3
bbs IN A 172.30.7.3
4:在测试服务器上绑定DNS的IP ,即可
5:这时候就可以ping通www.b.com/bbs.b.com了
原文:http://www.cnblogs.com/happlyp/p/6418499.html