DNS Settings MS Server

Toms88 · 17 Nov 2012 at 14:28

Just wanted to check with you guys about how my DNS is setup in IPv4. On my DNS server (a51-serv01) i have the IPv4 DNS set to

Primary: 192.168.0.2 (thats the IP of the localhost)
Secondary: 8.8.4.4

However i was just setting up a new laptop on the domain and noticed that DHCP gave the laptop a primary DNS of 127.0.0.1 which obviously just loops back to the laptops address and thus couldnt find the DNS server to join my domain. I can manually set it to point to my server, but why is getting a loopback IP from DHCP?

Edit:

Checked in DHCP under the server options node and i see its set to 127.0.0.1 (why im not sure) but if i try and add 192.168.0.2 it says it cant find a DNS service on that IP :S

Deleted member 77746 · 17 Nov 2012 at 14:49

How is your network giving out DHCP addresses?

Toms88 · 17 Nov 2012 at 17:07

I have DHCP on my server.

Liquidfox · 17 Nov 2012 at 18:36

If you open DNS under Administrative Tools, is it running? Also, is DNS Server running in services?

SoundsGood · 17 Nov 2012 at 18:53

Can you do an nslookup against 192.168.0.2 from the server and from the laptop?

Deleted member 77746 · 17 Nov 2012 at 18:57

Unless you take some screenshots of your DHCP Scopes / DNS Scopes / IPCONFIGS then there isn't a lot people will be able to help you with. Can you provide some ?

Toms88 · 17 Nov 2012 at 21:57

Liquidfox said:
If you open DNS under Administrative Tools, is it running? Also, is DNS Server running in services?

It is running, although ive had some noncompliant errors just recently.

Issue:
The DNS server 192.128.0.2 on Local Area Connection did not successfully resolve the name _ldap._tcp.gc._msdcs.area51.local.

Impact:
Active Directory Domain Services (AD DS) operations that depend on locating a Global Catalog will fail.

Resolution:
Click Start, click Network, click Network and Sharing Center, and then click Change adapter settings to configure DNS servers that can resolve the name _ldap._tcp.gc._msdcs.area51.local.

I had recently changed the name of the server from the default WIN-THPXMH-etc to A51-Serv01, so i want sure if some records didnt update when i did the name change and thats causing a problem.

SoundsGood said:
Can you do an nslookup against 192.168.0.2 from the server and from the laptop?

I can do an nslookup against a51-serv01 from the laptop and the server. (not again the ip)

mrbell1984 said:
Unless you take some screenshots of your DHCP Scopes / DNS Scopes / IPCONFIGS then there isn't a lot people will be able to help you with. Can you provide some ?

C:\Users\Administrator>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : A51-SERV01
Primary Dns Suffix . . . . . . . : AREA51.LOCAL
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : Yes
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : AREA51.LOCAL

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82567LM-3 Gigabit Network Connec
tion
Physical Address. . . . . . . . . : 6C-F0-49-25-EA-92
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.0.2(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.128.0.2
8.8.4.4
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 9:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.{D474DBDE-62FB-4893-9326-26CF90765E12}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

C:\Users\Administrator>

DHCP IPv4 Scope Options

Option Name Vendor Value Class
003 Router Standard 192.168.0.1 None
006 DNS Servers Standard 127.0.0.1, 8.8.4.4 None
015 DNS Domain Name Standard area51.local None

The issue is i cant change the DNS server from 127.0.0.1 to 192.168.0.2 I did also seem a recommendation that the Primary DNS on a DNS server should be 127.0.0.1 or is that on the adapter settings no the DHCP scope?

Shad · 17 Nov 2012 at 22:50

Toms88 said:
I did also seem a recommendation that the Primary DNS on a DNS server should be 127.0.0.1 or is that on the adapter settings no the DHCP scope?

The adapter on the server. As far as I know the server should query itself first, then the local secondary. The local DNS servers should use a forwarder if they cannot resolve locally. Try setting it up so that you have your router as a forwarder IP and on your router set your external DNS there (e.g. Google or your ISP servers).

Your DHCP should be set so clients will use your local DNS servers rather than anything external, or you might end up in some odd situations where internal names don't always resolve.

And I suspect this all kinda started to fail when you renamed the server. Hindsight is a wonderful thing

Deleted member 77746 · 17 Nov 2012 at 23:04

Can you provide an ipconfig /all from that laptop that you are having an issue on please?

PS don't go changing settings on the dhcp side, where you said you tried to add the ip. the 127.0.0.1 is used to query itself first.

Toms88 · 17 Nov 2012 at 23:10

Shad said:
The adapter on the server. As far as I know the server should query itself first, then the local secondary. The local DNS servers should use a forwarder if they cannot resolve locally. Try setting it up so that you have your router as a forwarder IP and on your router set your external DNS there (e.g. Google or your ISP servers).

Your DHCP should be set so clients will use your local DNS servers rather than anything external, or you might end up in some odd situations where internal names don't always resolve.

And I suspect this all kinda started to fail when you renamed the server. Hindsight is a wonderful thing

Isnt it just. I got a excited and started installing everything without much thought as to the next steps. Its why i also have a area51.local domain, and a public domain of area-51zone.com Again, hindsight is a wonderful thing!

mrbell1984 said:
Can you provide an ipconfig /all from that laptop that you are having an issue on please?

PS don't go changing settings on the dhcp side, where you said you tried to add the ip. the 127.0.0.1 is used to query itself first.

Its not the laptop specifcally, its any device that is configured with DHCP be it the Xbox, iPad or laptop. All of them are given 127.0.0.1 as the primary DNS so they just try and resolve locally. I have to manually change it back to 192.168.0.2

Deleted member 77746 · 17 Nov 2012 at 23:12

I have a feeling that the name change has caused problems with DNS causing a confusion with DHCP offers.

DHCP SCOPE said:
006 DNS Servers Standard 127.0.0.1, 8.8.4.4 None

= Change ...

006 DNS Servers Standard 192.168.0.2

As already mentioned on your DNS you will also require to add a forwarder to 8.8.8.8/8.8.4.4, don't give these addresses out in DHCP. (Domain Properties > Forwarders > Add 8.8.8.8 / 8.8.4.4 > Apply)

Uhtred · 17 Nov 2012 at 23:28

Is the DNS server a domain controller? Run dcdiag if so. Silly question, have you rebooted the server since you renamed it? Is there a firewall running on the DNS server?

prj1865 · 17 Nov 2012 at 23:43

Your NIC has a primary DNS of 192.128.0.2 rather than 192.168.0.2

But yeah what the others have said is correct your server NIC DNS should be 192.168.0.2 (or 127.0.0.1). the DNS service should then have forwarders to 8.8.8.8 and 8.8.4.4. DHCP should be handing out a DNS server of 192.168.0.2 to clients.

Toms88 · 17 Nov 2012 at 23:45

It is the DC as well yes. Its been rebooted numerous times since the name change, although there is definitely still something lurking because when i goto server manager, roles and select DNS i get a message about adding the old name again, i just click no and carry on but it still has the name record somewhere it seems. I have the windows firewall configured more or less default.

I ran dcdiag, what does that do?

Toms88 · 17 Nov 2012 at 23:47

prj1865 said:
Your NIC has a primary DNS of 192.128.0.2 rather than 192.168.0.2

But yeah what the others have said is correct your server NIC DNS should be 192.168.0.2 (or 127.0.0.1). the DNS service should then have forwarders to 8.8.8.8 and 8.8.4.4. DHCP should be handing out a DNS server of 192.168.0.2 to clients.

Well spotted!

OK i follow with that, so what would i put as the secondary DNS for the NIC if i put the google dns servers into the lookup zone?

prj1865 · 17 Nov 2012 at 23:52

You don't need anything as a second DNS for your NIC.

I renamed a DC once using the netdom tool and it didn't seem to cause any issues. May be worth also trying that and following some of the checks.
http://www.petri.co.il/windows_2003_domain_controller_rename.htm

Deleted member 77746 · 18 Nov 2012 at 00:05

It's a good job that wasn't a bloody exam question I would have been shot for that!

Toms88 · 18 Nov 2012 at 00:08

prj1865 said:
You don't need anything as a second DNS for your NIC.

I renamed a DC once using the netdom tool and it didn't seem to cause any issues. May be worth also trying that and following some of the checks.
http://www.petri.co.il/windows_2003_domain_controller_rename.htm

That's the guide i followed when i did it, and it seemed to work fine. No errors were noted during the change and everything else seems fine.

Shad · 18 Nov 2012 at 09:27

Is it too late to reinstall and rebuild?

Just quickly with regards to your domain name, don't use anything on your internal network that can be resolved by external DNS. E.g. don't use your public domain name, use a private subdomain or something fictional that will never be public such as ad.area-51zone.com or corp.area-51zone.com.

Deleted member 77746 · 18 Nov 2012 at 13:21

After a reboot it shoud be easy to resolve now. Thread answers are there.