dns 설정을 하였는데 ip주소를 못 찾네요 도와주세요

DNS 공부할려고 DNS 설정을 하였는데
nslookup을 하면

[root@ns ~]# nslookup www.xxx.com
Server: 192.168.5.5
Address: 192.168.5.5#53

** server can't find www.xxx.com: SERVFAIL

이렇게 뜹니다
어디가 뜰렸길레 재디로 안나오는걸까요?
아래는 설정 파일들 입니다
-------------------------
named.conf
-------------------------
options
{
// Put files that named is allowed to write in the data/ directory:
directory "/var/named"; // "Working" directory
dump-file "data/cache_dump.db";
statistics-file "data/named_stats.txt";
memstatistics-file "data/named_mem_stats.txt";
listen-on port 53 { 192.168.5.5; 127.0.0.1; };
//query-source address=port 53;
allow-query { any; };
allow-query-cache { any; };

recursion yes;
};

zone "localhost.localdomain" IN {
type master;
file "named.localhost";
allow-update { none; };
};

zone "localhost" IN {
type master;
file "named.localhost";
allow-update { none; };
};

zone "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
type master;
file "named.loopback";
allow-update { none; };
};

zone "1.0.0.127.in-addr.arpa" IN {
type master;
file "named.loopback";
allow-update { none; };
};

zone "0.in-addr.arpa" IN {
type master;
file "named.empty";
allow-update { none; };
};

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

$ORIGIN xxx.com.
$TTL 86400
@ IN SOA ns root (
2013122712 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
IN NS ns.

ns. IN A 192.168.5.5
time. IN A 192.168.5.3
www. IN A 192.168.5.5
~
~
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