DNS不能解析

我的DNS架好之后在nslookup中不能解析,但是可以PING通.以下是配置文件:

/var/named/dns.arpa
$TTL 86400
@ IN SOA dns.com. admin.dns.com. (
77191
604800
86400
2419200
604800 )
@ IN NS dns.com.
117 IN PTR mail.dns.com.
117 IN PTR www.dns.com.
117 IN PTR ns.dns.com.

/var/named/dns.zone
$TTL 86400
$ORIGIN dns.com.
@ IN SOA ns.dns.com. admin.dns.com. (
511
1H
15M
1W
1D )
IN NS ns.dns.com.
ns IN A 192.168.2.117
www IN A 192.168.2.117
mail IN A 192.168.2.117
dns.com IN MX 10 mail.dns.com.


/etc/named.conf
zone "dns.com" IN {
type master;
file "dns.zone";
};
zone "2.168.192.in-addr.arpa" IN {
type master;
file "dns.arpa";
};