# Nslookup



## IT-Barry (Sep 6, 2010)

Via DNS > Right click > Launch nslookup
This works fine

However loading up command prompt seperatly and typing nslookup command works, but server name is set to UnKnown and all attempts to get a lookup ip or name returns "no response from server"

Any idea how to fix this as its creating issues with dns/name resolution.

SBS 2011 - 2008 R2


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## Noobus (Oct 21, 2011)

IT-Barry said:


> Via DNS > Right click > Launch nslookup
> This works fine
> 
> However loading up command prompt seperatly and typing nslookup command works, but server name is set to UnKnown and all attempts to get a lookup ip or name returns "no response from server"
> ...


Hi IT-Barry,

Are you able to post a screenshot of an "ipconfig /all"

Have you got a single dns server on you network or more than one?
Do you get the same issue for other servers or workstations?

L


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## IT-Barry (Sep 6, 2010)

Single dns server which is the same server.

Also workstations nslookup works fine.

Having looked at the ipconfig I see the ipv6 is most likely the issue.

Some steps to sort it out, a.k.a get rid of ipv6 as I notice it has 2 seperate ones.


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## Wand3r3r (Sep 17, 2010)

in dns server do you have a (NS) listing with the servers name/ip address?

two nics in the server?

how about a nslookup from both the server and workstation for comparison?


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## buzza24 (Mar 27, 2008)

Sometimes it is better to use the loop back address (127.0.0.1) to point to itself rather than an actual IP.

Also check your Dns server configuration. Things like DNS forwarders etc?

Let's us know how you go.


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## Dave Atkin (Sep 4, 2009)

Hi Barry,

This may help:
Troubleshooting DNS 

"Can't find server name for ....: No response from server - DNS Request Timed Out

Symptom: When running nslookup, you may receive this message: Can't find server name for ....: No response from server

Cause: the DNS server's reverse lookup zones do not contain a PTR record for the DNS server's IP address. Refer to case 0204BL"

Also:
Nslookup 


Dave


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## IT-Barry (Sep 6, 2010)

Just the one NIC



> XP via direct command prompt
> C:\Documents and Settings\barry>nslookup
> Default Server: server-x.x.x
> Address: 192.168.20.10
> ...





> Server via directly command prompting
> C:\Users\admin>nslookup
> Default Server: UnKnown
> Address: fe80::d2a0:559a:27f2:1cf2
> ...


*If I go via Admin tools > DNS > right click Launch NSlookup on the server I get the working way that the XP shows.*

DNS has a ptr record for the server - 192.168.20.10 server-x.x.x
Server is also in as SQA Start of authority and as a name server(NS), also a WINS lookup.

I have cnames for companyweb etc that point to the serversname in forward.

Also the record for the server in forward lookup is in as same as parent(sure thats fine)
*
EDIT - Unchecking IPV6 on the NIC has got the nslookup working via direct command prompt but server name is still in as "UnKnown"*


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## IT-Barry (Sep 6, 2010)

IT-Barry said:


> EDIT - Unchecking IPV6 on the NIC has got the nslookup working via direct command prompt but server name is still in as "UnKnown"[/SIZE][/B]


Unchecking the IPV6 breaks the connection between outlook and the server so I have reverted it for now.

Exchange 2010 must use IPV6 or something.

Any help on
a) fixing the bug where if I uncheck IPV6 outlook cant connect to the server and the unknown server thing as dns looks good to me as per my post above
b) alternative to fix nslookup if disabling IPV6 cant be done due to exchange.


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## Wand3r3r (Sep 17, 2010)

appears you only have ipv6 on the server not ipv4.

Command is not just nslookup. That puts you at the prompt.

type nslookup servername from the server and from the workstation and post the results.

You don't need to x anything out unless its your last name on the prompt.

also post a ipconfig /all from both for review also


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## IT-Barry (Sep 6, 2010)

I have no issue with xp.

Only issue I have is the server, see attachment.
Top is via command prompt
Bottom is via Admin tools > DNS > Right click Launch NSlookup.(I have also fixed the Unknown on the bottom one shows the servername now)

How do I fix this, ipconfig is above.

Server ip is 192.168.20.10, server name is blocked out as it can be accessed via public side so dont want people spamming it.

Pinging server-x.x.x results in it returning the ipv6 ip, this is now the issue.

How do I make the servers primary IP set to V4


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## Wand3r3r (Sep 17, 2010)

Hard to help someone when they don't supply requested info.

Go into the advanced settings for the server nic so you can change the binding order.


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## IT-Barry (Sep 6, 2010)

Wand3r3r said:


> appears you only have ipv6 on the server not ipv4.
> *the server has the ip 192.168.20.10 along with ipv6, the ip is accessible as a share, and thats the ip tht appears in ipconfig on a workstation for dns/dhcp*
> 
> type nslookup servername from the server and from the workstation and post the results.
> ...


I did try your suggestions I simply didnt see anything from them that would be useful.


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## Dave Atkin (Sep 4, 2009)

Can you temporarily change the DNS Server to something else (for example the rotuer) just to see if you get the same error when using an alternate server for lookups?

I'm guessiong that there is nothing relivant in the event logs?


Dave


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## smartguykkd (Oct 8, 2010)

check the pointer record is correctly mapped to the A record
create a new pointer record and map it to A record and check it

i had faced the same problem and i solved in this way


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