Nslookup query

[Guest]

Hi all,

I have this question in mind, but i have no idea how and where to start to
clear the question. Please help to provide some guide and info.

I have own internal DNS and configure forwarder to external dns. Everytime
when i use nslookup command, by default it will point to external dns. I just
wonder why the default DNS is not pointing to my internal dns by default? In
this case, is that mean everytime i have a DNS query, it will directly
forward to the external DNS & will not go thru my internal DNS?

Please help. Thanks.

 

[Deji Akomolafe]

This just means that the computer you are running nslookup on is using the
external DNS in its TCP/IP configuration. It's either set there manually, or
your DHCP server is giving it out. You need to change this.

--

Sincerely,
Dèjì Akómöláfé, MCSE+M MCSA+M MCP+I
Microsoft MVP - Directory Services
www.readymaids.com - we know IT
www.akomolafe.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon

 

[Ace Fekay [MVP]]

In

This just means that the computer you are running nslookup on is
using the external DNS in its TCP/IP configuration. It's either set
there manually, or your DHCP server is giving it out. You need to
change this.

Hi Deji,

I just want to add that's a good idea to change it too if running an AD
infrastructure. If the ISP's DNS address is in their IP properties, that
would mean the machines are misconfigured for proper AD functionality.

(Just a reminder to the original poster if this is an AD infrastructure, you
must only use the internal DNS servers hosting the AD zone name or if you
mix them with the ISP's, predicatable unknown issues will occur).

--
Ace

This posting is provided "AS-IS" with no warranties or guarantees and
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If this post is viewed at a non-Microsoft community website, and you were to
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Therefore, please direct all replies ONLY to the Microsoft public newsgroup
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posts it back to the original forum.

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft MVP - Windows Server Directory Services
Microsoft Certified Trainer
Infinite Diversities in Infinite Combinations.
=================================

 

[Guest]

Hi Deji, Ace,

Thanks for the reply. I still new to AD environment. I have following
followup question. Please advice.

I have 2 internal DNS Servers locally and addtional DNS in main
office(connect thru WAN VPN). DHCP configure both internal DNS as primary and
secondary with addtional third DNS as main office DNS IP. When i use
nslookup, the following message display:

C:\>nslookup
*** Can't find server name for address 10.192.2.1: Non-existent domain
*** Can't find server name for address 10.192.2.2: Non-existent domain
Default Server: AD-Test
Address: 10.193.2.3

Please advice why both internal DNS will have the message "Non-Existent
domain"? Is it because of misconfiguration of the DNS configuration ?

In this situation, is that mean all the DNS query is actually directly go to
10.192.2.3 to resolve and the forwarder i configure on internal DNS
(10.192.2.1 & 10.192.2.2) will not perform the job to forward the DNS query
to external DNS at all?

Please advice.

Thanks in advance.

 

[Kevin D. Goodknecht Sr. [MVP]]

Hi Deji, Ace,

Thanks for the reply. I still new to AD environment. I have following
followup question. Please advice.

I have 2 internal DNS Servers locally and addtional DNS in main
office(connect thru WAN VPN). DHCP configure both internal DNS as
primary and secondary with addtional third DNS as main office DNS IP.
When i use nslookup, the following message display:

C:\>nslookup
*** Can't find server name for address 10.192.2.1: Non-existent domain
*** Can't find server name for address 10.192.2.2: Non-existent domain
Default Server: AD-Test
Address: 10.193.2.3

Please advice why both internal DNS will have the message
"Non-Existent domain"? Is it because of misconfiguration of the DNS
configuration ?

It is because there is no PTR records for these two addresses on these
servers, and nslookup, like the system DNS resolver will stick with the
first DNS server that provides an answer.
Create PTR records for these addresses and the message will go away.

 

[Ace Fekay [MVP]]

In

Hi Deji, Ace,

Thanks for the reply. I still new to AD environment. I have following
followup question. Please advice.

I have 2 internal DNS Servers locally and addtional DNS in main
office(connect thru WAN VPN). DHCP configure both internal DNS as
primary and secondary with addtional third DNS as main office DNS IP.
When i use nslookup, the following message display:

C:\>nslookup
*** Can't find server name for address 10.192.2.1: Non-existent domain
*** Can't find server name for address 10.192.2.2: Non-existent domain
Default Server: AD-Test
Address: 10.193.2.3

Please advice why both internal DNS will have the message
"Non-Existent domain"? Is it because of misconfiguration of the DNS
configuration ?

In this situation, is that mean all the DNS query is actually
directly go to
10.192.2.3 to resolve and the forwarder i configure on internal DNS
(10.192.2.1 & 10.192.2.2) will not perform the job to forward the DNS
query to external DNS at all?

Please advice.

Thanks in advance.

"c.s" wrote:

Kevin explained why the 'can't find servername...' message is appearing.

As for the queries, since 10.192.2.3 is the first entry in your IP config,
nslookup will use that entry for queries. If the query is of a name that
10.192.2.3 cannot resolve, that DNS will use the forwarder confgured,
assuming it is configured to use your ISP's. Make sure you don't forward to
each other in an infrastructure, unless you are utilizing delegations.

Ace

 

[Guest]

Hi all,

Thanks for all the help and reply.

Many thanks.

 

[Ace Fekay [MVP]]

Hi all,

Thanks for all the help and reply.

Many thanks.

No prob!

Ace

 

[Jorge_de_Almeida_Pinto]

Hi Deji, Ace,

Thanks for the reply. I still new to AD environment. I have
following
followup question. Please advice.

I have 2 internal DNS Servers locally and addtional DNS in
main
office(connect thru WAN VPN). DHCP configure both internal DNS
as primary and
secondary with addtional third DNS as main office DNS IP. When
i use
nslookup, the following message display:

C:>nslookup
*** Can't find server name for address 10.192.2.1:
Non-existent domain
*** Can't find server name for address 10.192.2.2:
Non-existent domain
Default Server: AD-Test
Address: 10.193.2.3

Please advice why both internal DNS will have the message
"Non-Existent
domain"? Is it because of misconfiguration of the DNS
configuration ?

In this situation, is that mean all the DNS query is actually
directly go to
10.192.2.3 to resolve and the forwarder i configure on
internal DNS
(10.192.2.1 & 10.192.2.2) will not perform the job to forward
the DNS query
to external DNS at all?

Please advice.

Thanks in advance.

It looks like you have multiple DNS servers specified in the TCP/IP
settings. Only use internal DNS servers! (if it is an internal server
belonging to AD)

The reason the first 2 gave an "error" is because you don’t have a
reverse lookup zone so that the IP in the DNS settings to resolve it
to a FQDN. The third does not give the same error because you have a
reverse lookup zone for it.

As the other guys already said, configure your internal servers to
only point to internal DNS servers. On the internal DNS servers
configure forwarders and/or root hints