Some DNS servers fails to resolve address

Hi,

I have been battling with the DNS setup for a few weeks.

We have set up a website www.soopod.com, one of the subdomain it has is
hz1.soopod.com. I configured a zone file for the soopod.com zone and on
Red Hat server.

Previously, this domain has two name servers but we only set up the
primary. This caused problems in some DNS server. So at the moment we
decide to use only one name server ns1.excenon.com and remove the
other. I made this change 5 days ago. This solves some lookup problems

But some DNS servers still keep having problems. The symptoms are
always that the DNS servers can nslookup www.sopod.com without any
problem but cannot resolve subdomains like hz1.soopod.com. I tried
other subdomains like ftp.soopod.com, same problem. Sometimes, a DNS
server can resolve the address at one time but the other.

The questions are:
(1) Why some DNS servers will not be able to resolve the address but
others can?
(2) Why does it seem to occur more for subdomains?

I would tend to blame the DNS server but they seem to be able resolve
other addresses without much trouble,

Thanks for any help!

My zone file content:

[root@ns1 named]# pwd; cat soopod.com.hosts
/var/named/chroot/var/named
$ttl 3D
@ IN SOA ns1.excenon.com. webmaster.excenon.com. (
20060527
10800
3600
604800
3D )
;
NS www ; Inet address of name server

soopod.com. MX 0 202.105.139.204
soopod.com. IN A 202.105.139.204
www.soopod.com. IN A 61.175.162.38
mail.soopod.com. IN A 202.105.139.204
ftp.soopod.com. IN A 61.175.162.38
pop.soopod.com. IN CNAME mail.soopod.com.
smtp.soopod.com. IN CNAME mail.soopod.com.
hz1.soopod.com. IN CNAME www.soopod.com.

BTW Here is an example of nslookup results:

$ nslookup www.soopod.com 202.96.134.133
Server: ns.szptt.net.cn
Address: 202.96.134.133

Non-authoritative answer:
Name: www.soopod.com
Address: 61.175.162.38


wquock@HAWAII ~
$ nslookup hz1.soopod.com 202.96.134.133
Server: ns.szptt.net.cn
Address: 202.96.134.133

DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to ns.szptt.net.cn timed-out

(E-Mail Removed) wrote:
> Hi,
>
> I have been battling with the DNS setup for a few weeks.
>
> We have set up a website www.soopod.com, one of the subdomain it has is
> hz1.soopod.com. I configured a zone file for the soopod.com zone and on
> Red Hat server.
>
> Previously, this domain has two name servers but we only set up the
> primary. This caused problems in some DNS server. So at the moment we
> decide to use only one name server ns1.excenon.com and remove the
> other. I made this change 5 days ago. This solves some lookup problems
>
> But some DNS servers still keep having problems. The symptoms are
> always that the DNS servers can nslookup www.sopod.com without any
> problem but cannot resolve subdomains like hz1.soopod.com. I tried
> other subdomains like ftp.soopod.com, same problem. Sometimes, a DNS
> server can resolve the address at one time but the other.
>
> The questions are:
> (1) Why some DNS servers will not be able to resolve the address but
> others can?
> (2) Why does it seem to occur more for subdomains?
>
> I would tend to blame the DNS server but they seem to be able resolve
> other addresses without much trouble,
>
> Thanks for any help!
>
> My zone file content:
>
> [root@ns1 named]# pwd; cat soopod.com.hosts
> /var/named/chroot/var/named
> $ttl 3D
> @ IN SOA ns1.excenon.com. webmaster.excenon.com. (
> 20060527
> 10800
> 3600
> 604800
> 3D )
> ;
> NS www ; Inet address of name server

Your (primary) nameserver is ns1.excenon.com, not www.soopod.com!

> soopod.com. MX 0 202.105.139.204
> soopod.com. IN A 202.105.139.204
> www.soopod.com. IN A 61.175.162.38
> mail.soopod.com. IN A 202.105.139.204
> ftp.soopod.com. IN A 61.175.162.38
> pop.soopod.com. IN CNAME mail.soopod.com.
> smtp.soopod.com. IN CNAME mail.soopod.com.
> hz1.soopod.com. IN CNAME www.soopod.com.
>

Thanks!

I kept missing that "NS" setting in the zone file, thinking it is just
cosmetic.

Now, the server can resolve:

$ nslookup hz1.soopod.com 202.96.134.133
Server: ns.szptt.net.cn
Address: 202.96.134.133

Non-authoritative answer:
Name: www.soopod.com
Address: 61.175.162.38
Aliases: hz1.soopod.com