Cannot dig ip from dns name

Hi, guys,

I try to use dig to acquire the ip of a dns name, but fail.
The machine does connect to the dns server because the website I tried with
dig can actually accessed via firefox or other browser.

BTW, the machine I used is behind the gateway of our company, does this
gateway cause the failure of dig command?

Thank you for answer this question that confuse me for long time.

Justin
10/20

On Mon, 20 Oct 2008 21:09:56 +0800, Jking wrote:

> I try to use dig to acquire the ip of a dns name, but fail. The machine
> does connect to the dns server because the website I tried with dig can
> actually accessed via firefox or other browser.
>
> BTW, the machine I used is behind the gateway of our company, does this
> gateway cause the failure of dig command?

Yes, or No...

> Thank you for answer this question that confuse me for long time.

Does this problem relate to only 1 single hostname?

How do you invoke dig?

What's your content of /etc/resolv.conf?

What's the actual output from dig?


--
Regards/mvh Joachim Mæland

If everything seems under control, you're just not going fast enough.
-Mario Andretti

Hello,

Jking a écrit :
>
> I try to use dig to acquire the ip of a dns name, but fail.

Can you elaborate a bit ?

> The machine does connect to the dns server because the website I tried with
> dig can actually accessed via firefox or other browser.

Not necessarily. If the browser uses a proxy, then it does not need to
do DNS lookups.

Sorry, please see the following supplement information:

$cat /etc/resolv.conf

domain ds.codeline.com
search ds.codeline.com
nameserver 10.193.143.1
nameserver 129.188.1.1
nameserver 129.188.2.2

$dig www.google.com

;<<>> DiG 9.3.4 <<>> www.google.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55822
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.google.com. IN A

;; AUTHORITY SECTION: com. 7867 IN SOA dns0.corp.codeline.com.
dnssupport.codeline.com. 2000179475 3600 600 604800 14400

;; Query time: 32 msec
;; SERVER: 10.193.143.1#53(10.193.143.1)
;; WHEN: Mon Oct 20 23:01:51 2008
;; MSG SIZE rcvd: 102

"Joachim M?land" <jm-(E-Mail Removed)> дÈëÏûÏ¢ÐÂÎÅ:31dus5-(E-Mail Removed)...
> On Mon, 20 Oct 2008 21:09:56 +0800, Jking wrote:
>
>> I try to use dig to acquire the ip of a dns name, but fail. The machine
>> does connect to the dns server because the website I tried with dig can
>> actually accessed via firefox or other browser.
>>
>> BTW, the machine I used is behind the gateway of our company, does this
>> gateway cause the failure of dig command?
>
> Yes, or No...
>
>> Thank you for answer this question that confuse me for long time.
>
> Does this problem relate to only 1 single hostname?
>
> How do you invoke dig?
>
> What's your content of /etc/resolv.conf?
>
> What's the actual output from dig?
>
>
> --
> Regards/mvh Joachim M?land
>
> If everything seems under control, you're just not going fast enough.
> -Mario Andretti
>

On Mon, 20 Oct 2008 23:17:59 +0800, Jking wrote:

> nameserver 10.193.143.1
> nameserver 129.188.1.1
> nameserver 129.188.2.2

Please give this a go:

$ dig @129.188.1.1 www.google.com
$ dig @129.188.2.2 www.google.com

> $dig www.google.com
[..]
> ;; SERVER: 10.193.143.1#53(10.193.143.1) ;; WHEN: Mon Oct 20 23:01:51
> 2008
> ;; MSG SIZE rcvd: 102

10.193.143.1 is clearly not providing the answer...

--
Regards/mvh Joachim Mæland

If everything seems under control, you're just not going fast enough.
-Mario Andretti

"Pascal Hambourg" <boite-a-(E-Mail Removed)>
??????:gdi31m$2k5h$(E-Mail Removed)...
> Hello,
>
> Jking a écrit :
>>
>> I try to use dig to acquire the ip of a dns name, but fail.
>
> Can you elaborate a bit ?
>
>> The machine does connect to the dns server because the website I tried
>> with dig can actually accessed via firefox or other browser.
>
> Not necessarily. If the browser uses a proxy, then it does not need to do
> DNS lookups.

Yes, a proxy server on the LAN of the company provide the proxy to internet.
But I doubt that the browser does not need to do dns lookup is an "always"
or "may be" situation?
>

I have tried, but the other two servers still do not provide the answer.
"Joachim M?land" <jm-(E-Mail Removed)> дÈëÏûÏ¢ÐÂÎÅ:djmus5-(E-Mail Removed)...
> On Mon, 20 Oct 2008 23:17:59 +0800, Jking wrote:
>
>> nameserver 10.193.143.1
>> nameserver 129.188.1.1
>> nameserver 129.188.2.2
>
> Please give this a go:
>
> $ dig @129.188.1.1 www.google.com
> $ dig @129.188.2.2 www.google.com
>
>> $dig www.google.com
> [..]
>> ;; SERVER: 10.193.143.1#53(10.193.143.1) ;; WHEN: Mon Oct 20 23:01:51
>> 2008
>> ;; MSG SIZE rcvd: 102
>
> 10.193.143.1 is clearly not providing the answer...
>
> --
> Regards/mvh Joachim M?land
>
> If everything seems under control, you're just not going fast enough.
> -Mario Andretti

Jking a écrit :
>
> Yes, a proxy server on the LAN of the company provide the proxy to internet.
> But I doubt that the browser does not need to do dns lookup is an "always"
> or "may be" situation?

I don't understand your last sentence. What do you mean ?

Hmm, I am just not sure about that when a browser is set to access internet
via proxy server, it always delegate the responsibility of dns lookup to
proxy server, or may have other choice to look up dns name by itself?

"Pascal Hambourg" <boite-a-(E-Mail Removed)>
??????:gdk8a1$305c$(E-Mail Removed)...
> Jking a écrit :
>>
>> Yes, a proxy server on the LAN of the company provide the proxy to
>> internet.
>> But I doubt that the browser does not need to do dns lookup is an
>> "always" or "may be" situation?
>
> I don't understand your last sentence. What do you mean ?

Jking a écrit :
> Hmm, I am just not sure about that when a browser is set to access internet
> via proxy server, it always delegate the responsibility of dns lookup to
> proxy server,

Yes, AFAIK.

> or may have other choice to look up dns name by itself?

AFAIK this would be useless, as the HTTP query sent to the proxy server
contains the host name, not the IP address.