** server can't find .: SERVFAIL when query "."

[Truong Tan Son]

Dear Sir,

I    installed Bind-9.3.2 on RedHat EL4

Server resolves     name --> IP:       Ok
                            IP   ---> name:    Ok 

But ** server can't find .: SERVFAIL when query "."

On client I did:
#nslookup
> server 172.16.134.85
Default server: 172.16.134.85
Address: 172.16.134.85#53
> set type=ns
> .
Server:         172.16.134.85
Address:        172.16.134.85#53

** server can't find .: SERVFAIL
                                ^^^^^^^^^^
#dig @172.16.134.85
; <<>> DiG 9.3.2 <<>> @172.16.134.85; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 20539
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;.                              IN      NS

;; Query time: 3 msec
;; SERVER: 172.16.134.85#53(172.16.134.85)
;; WHEN: Fri Dec 23 12:16:02 2005
;; MSG SIZE  rcvd: 17



---------------------------
THE  CONFIG     FILE
---------------------------
#cat /usr/local/named/etc/named.conf
options {
        directory "/usr/local/named/etc";
        allow-query { any;};
        allow-transfer { any;};
};
zone    "." in {
        type master;
        file "named.ca";
..
..
#cat /usr/local/named/etc/named.ca
.                        3600000  IN  NS    A.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET.      3600000      A     198.41.0.4
;
; formerly NS1.ISI.EDU
;
.                        3600000      NS    B.ROOT-SERVERS.NET.
B.ROOT-SERVERS.NET.      3600000      A     128.9.0.107

...
...



What is  SERVFAIL, and should I do ?

Please advise me.

Thanks you and best regards,
---