dns 설정하는데 오류가 납니다

사설 네트워크에서 독립으로 DNS 서비스를 하고 싶어서
여기저기 찾아보고 설정을 해봤습니다

그런데 named 서비스를 재시작을 하면 아래와 같은 오류 메세지가 나오네요

0.168.192.in-addr.arpa/IN: has no NS records
fileserver.co.kr/IN: has no NS records

대체 왜 has no NS records 가 나오는지 모르겠습니다

제 설정 파일을 올리니 부디 아시는 분은 알려주시면 감사하겠습니다...ㅠ.ㅠ

그리고 nslookup을 하면 아래와 같은 에러가 나옵니다

[root@fileserver sysconfig]$ nslookup localhost
Server:         192.168.0.31
Address:        192.168.0.31#53

Name:   localhost
Address: 127.0.0.1

[root@fileserver sysconfig]$ nslookup fileserver.co.kr
Server:         192.168.0.31
Address:        192.168.0.31#53

** server can't find fileserver.co.kr: SERVFAIL

[root@fileserver sysconfig]$ nslookup 127.0.0.1
Server:         192.168.0.31
Address:        192.168.0.31#53

1.0.0.127.in-addr.arpa  name = localhost.

[root@fileserver sysconfig]$ nslookup 192.168.0.31
Server:         192.168.0.31
Address:        192.168.0.31#53

** server can't find 31.0.168.192.in-addr.arpa: SERVFAIL

설정 파일들
==========================================================
/etc/hosts
==========================================================
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1       localhost       localhost.localdomain
192.168.0.31    fileserver      fileserver.co.kr

==========================================================
/etc/resolv.conf
==========================================================
nameserver 192.168.0.31

==========================================================
/etc/sysconfig/network
==========================================================
NETWORKING=yes
HOSTNAME=fileserver.co.kr

==========================================================
/etc/named.conf
==========================================================
//
// named.conf for Red Hat caching-nameserver
//

options {
        directory "/var/named";
        dump-file "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        /*
         * If there is a firewall between you and nameservers you want
         * to talk to, you might need to uncomment the query-source
         * directive below.  Previous versions of BIND always asked
         * questions using port 53, but BIND 8.1 uses an unprivileged
         * port by default.
         */
         // query-source address * port 53;
};

//
// a caching only nameserver config
//
controls {
        inet 127.0.0.1 allow { localhost; } keys { rndckey; };
};

zone "." IN {
        type hint;
        file "named.ca";
};

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

zone "0.0.127.in-addr.arpa" IN {
        type master;
        file "named.local";
        allow-update { none; };
};

zone "0.168.192.in-addr.arpa" IN {
        type master;
        file "fileserver.rev";
        allow-update { none; };
};

zone "fileserver.co.kr" IN {
        type master;
        file "fileserver.zone";
        allow-update { none; };
};

include "/etc/rndc.key";
~                                    

==========================================================
/var/named/fileserver.zone
==========================================================

$TTL 86400
@ IN SOA ns.fileserver.co.kr. root.fileserver.co.kr. (
200810021       ; serial (d. adams)
3H              ; refresh
15M             ; retry
1W              ; expiry
1D )            ; minimum
IN NS ns.fileserver.co.kr.

IN A 192.168.0.31
IN HINFO "DNS" "FILESERVER"
IN MX 10 mail.fileserver.co.kr.

ns IN A 192.168.0.31
mail IN A 192.168.0.31

==========================================================
/var/named/fileserver.rev
==========================================================

$TTL 86400
@ IN SOA ns.fileserver.co.kr. root.fileserver.co.kr. (
200810021 ; Serial
28800      ; Refresh
14400      ; Retry
3600000    ; Expire
86400 )    ; Minimum
IN NS ns.fileserver.co.kr.
31 IN PTR fileserver.co.kr.

==========================================================
named 를 재시작하면 나오는 메세지들입니다.
/var/log/messages
==========================================================

Oct  2 17:24:06 fileserver named: named ?쒖옉 succeeded
Oct  2 17:24:06 fileserver named[29176]: listening on IPv4 interface lo, 127.0.0.1#53
Oct  2 17:24:06 fileserver named[29176]: listening on IPv4 interface eth0, 192.168.0.31#53
Oct  2 17:24:06 fileserver named[29176]: command channel listening on 127.0.0.1#953
Oct  2 17:24:06 fileserver named[29176]: zone 0.0.127.in-addr.arpa/IN: loaded serial 1997022700
Oct  2 17:24:06 fileserver named[29176]: zone 0.168.192.in-addr.arpa/IN: has no NS records
Oct  2 17:24:06 fileserver named[29176]: zone fileserver.co.kr/IN: has no NS records
Oct  2 17:24:06 fileserver named[29176]: zone localhost/IN: loaded serial 42
Oct  2 17:24:06 fileserver named[29176]: running

부디 알려주세요...ㅠ.ㅠ