nslookup <ip addr> works, but not nslookup <dns name>

[cpjust]

Hi,
I'm not an IT guy, so I'm not a DNS expert or anything...

I have a Win2003 server on a workgroup, not a domain (used for testing, so I don't care about domains...), and when I run: nslookup 10.0.81.1 (IP Address for that machine), it resolves to a DNS name computer.domain.com (I'm not sure where the domain suffix comes from, but the machine name is right).
But if I run: nslookup computer.domain.com it can't resolve the address.

Also, I can ping the IP Address and name (without the domain), but I can't ping computer.domain.com.

When I look on the DNS server (another Win2003 server) I don't see the server name or IP address in the forward or reverse lookup zones.
BTW, in the TCP/IP properties, DNS tab, I have the box checked to automatically register the machine with DNS...

Why is nslookup only working with the IP Address, and why is it appending a domain to a machine that isn't on a domain?

 

[TweakMYbox]

When you run nslookup on the computer in question, when it resolves the computername.domain.com, is it the same domain.com that you would get if you ran an nslookup on the DNS server?

In your network settings, on the DNS tab, do you have a check next to 'Append parent suffixes of the primary DNS suffix' checked?

Is your DNS server a member of a domain, or a stand-alone?

Mike Fegan, MCSA, MCSE

http://www.tweakmybox.com

Vote on the Babe of the Week, and talk shop with other techies at

http://www.tweakmybox.com!

 

[cpjust]

When you run nslookup on the computer in question, when it resolves the computername.domain.com, is it the same domain.com that you would get if you ran an nslookup on the DNS server?

Yes.

In your network settings, on the DNS tab, do you have a check next to 'Append parent suffixes of the primary DNS suffix' checked?

Yes.

Is your DNS server a member of a domain, or a stand-alone?

It's a domain server of a sub-domain. i.e. dc1.subdomain1.otherdomain.com

I have 4 DNS servers listed in the DNS tab.
The first is the DC listed above.
The other 3 are in a completely different domain.
i.e.:
DNS1 = dc1.subdomain.otherdomain.com
DNS2 = dc1.domain.com
DNS3 = server.domain.com
DNS4 = dc2.domain.com

When I run nslookup 10.0.81.1 on the 10.0.81.1 machine or DNS1, I get:

Server:  dc1.subdomain.[b]otherdomain.com[/b]
Address:  10.0.10.56

Name:    computer.[b]domain.com[/b]
Address:  10.0.81.1

 

[TweakMYbox]

Good info... one last question, is DNS integrated into AD?

Mike Fegan

http://www.keepAUSTINhosted.com

Affordable Web Hosting, SSL Certs, and much more... from the "weirdest" city in Texas.

 

[cpjust]

How can I tell if DNS is integrated into AD? (I'm not even sure what that means?)

 

[TweakMYbox]

Being that your DNS servers are named DC, I am assuming that you have an Active Directory integrated DNS. In order for your workstation to automatically register with DNS, the computer would have to be part of the domain.

Mike Fegan

http://www.keepAUSTINhosted.com

Affordable Web Hosting, SSL Certs, and much more... from the "weirdest" city in Texas.

 

[cpjust]

OK, that sounds about right, and my server isn't part of any domain - it's just in a workgroup.
So does this help explain why only the IP Address is being resolved or why domain.com is being appended to the name that gets resolved?
I don't have anything in the "Domain suffix to append" boxes. I also don't see the name or IP address listed in the forward or reverse lookup zones on any of the DNS servers.

 

[Cstorms]

In your dns configuration on the client machine the circle box for appending the primary and connection specific dns is probably selected then since you by default have 1 of the 2 selected. This would explain the domain.com part yes, and as for why your ip is the only thing being returned what probably is happening is your dns server is accepting dynamic updates but not creating associate ptr records, so you can query the ns server for the A record associated to the ip but you arent able to do a reverse lookup since *probably* there are none dynamically created for it... Thats my stab at it. Good luck. (if anyone needs to critique my explanation please do so in case I may have slaughtered anything)

 

[cpjust]

But if it's appending the domain suffix from the DNS server, wouldn't it use the domain from DNS1 which is different than the other DNS server domains? Or could DNS1 not allow dynamic updates, and then it tries to do a dynamic update to the next DNS server and use its suffix...?

But I don't see 10.0.81.1 on any of the DNS servers, so I just had another thought:
Is it possible that nslookup 10.0.81.1 is either directly or indirectly querying 10.0.81.1 for the name if the DNS server doesn't know?

 

[Cstorms]

If the computer is joined to the domain, meaning it is using a dns server with an AD integrated zone, it would append whatever the zone name (pretty much the domain name) is in there. If you have Append parent suffixes unchecked it will not append the extra levels of names you may have... Therefore client.subzone.zone.com would actually end up looking like client.zone.com (by zone in most cases would mean domain).... man I hope I have that right, if not it could become really sticky, but I am confident in that response so take it for what its worth.

 

[cpjust]

If the computer is joined to the domain

It's not a member of any domain, it's just in a workgroup.


It sounds like the resolved name I should be seeing is:
computer.xyz.com
or
computer.subdomain.xyz.com

but what I'm actually getting is:
computer.abc.com (where abc.com is the domain that DNS2, 3, & 4 are members or DCs for).