DNS suffix problem

paradigm

paradigm

paradigm

Caporegime
Joined
26 Aug 2003
Posts
37,508
Location
Leafy Cheshire
Wasn't sure if this belonged in Networks or here, but given that its all windows OS's that are involved in the problem, and its not physical networking as such, I thought here seemed more fitting.

I'm having a random DNS issue, that I swear I was not having a few months ago. I have a laptop that is a member of our Active Directory domain at work (lets call this abcd.com). If I were to ping a netbios name (such as computer1), the correct machine would be looked up, and resolved as computer1.abcd.com [10.1.1.200]. This is fine, and behaviour I would expect.

If however I take the laptop home, connect to the LAN here, the laptop sees the DHCP server (also an Active Directory Domain Controller), and is appending the correct DNS domain name (as set in the scope and server options of the DHCP server). The laptop will recieve a DHCP specified IP address, subnet mask, gateway address, DNS server addresses, and WINS addresses, as well as picking up my home domain DNS suffix (lets call this wxyz.com). If I now try pinging a local machine name, for example homepc1 (FQDN being homepc1.wxyz.com), the laptop returns homepc1.abcd.com, and (randomly) manages to ping an internet address (of which I have no idea what the IP is, nor do I really care).

What am I doing wrong?
 
Silly question;

What DNS addresses is the DHCP server on your home LAN set to give out? Prosumably just the DNS for your DC/DHCP Server? It's not giving any other addresses such as your home router etc out is it? Would be usefull to see a dump of you IPCONFIG /ALL if you don't mind

Also what is your domain name? Obviously it is resolving to something which could be a domain on the net answering for all subdomains. Do you have root hints and recursive lookups enabled in DNS on your DC?

Without more info it's hard for me to help further.

Are you logging on to the domain at home? If so are you re-joining to home>work>home?

Also is there anything manaully added in the TCP/IP advanced section on your laptop? Such as domain suffixes?
 
The addresses given out by my DHCP are as follows:

DNS: 10.1.0.5(secondary)
WINS: 10.1.0.5, 10.1.0.2 (secondary)
Gateway: 10.1.0.1

PC IP addresses are in the scope of 10.1.0.100 - 10.1.1.150, with a subnet mask of 255.255.0.0.

My domain name is paradigital.net, and work is eazyfonegroup.com.

I don't re-join the home domain when I get home, I just connect to the LAN, and use typed credentials to access anything on my AD.

Nothing is added to the advanced TCP/IP settings on the laptop.

Here is an IPCONFIG /all dump from HOME (actually taken from my desktop PC, which IS part of my AD):

Code: 
Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Elliott.Cummings>ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : COMPUTER02
   Primary Dns Suffix  . . . . . . . : paradigital.net
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : paradigital.net

   Connection-specific DNS Suffix  . : paradigital.net
   Description . . . . . . . . . . . : Realtek RTL8169/8110 Family PCI GBE NIC
   Physical Address. . . . . . . . . : 00-50-8D-xx-xx-xx
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::6184:7bc:92ff:70de%8(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.1.0.100(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.0.0
   Lease Obtained. . . . . . . . . . : 22 April 2009 07:26:15
   Lease Expires . . . . . . . . . . : 28 April 2009 07:26:12
   Default Gateway . . . . . . . . . : 10.1.0.1
   DHCP Server . . . . . . . . . . . : 10.1.0.5
   DNS Servers . . . . . . . . . . . : 10.1.0.5
   Primary WINS Server . . . . . . . : 10.1.0.5
   Secondary WINS Server . . . . . . : 10.1.0.2
   NetBIOS over Tcpip. . . . . . . . : Enabled
 
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Is the info in ipconfig the same on the laptop? Does your home PC ping the laptop ok? To me it sounds like one of the settings is hard set on your laptop as mentioned, either via Group Policy (Never really understood why people set it that way, i guess it is potentially usefull for suffix's) or manually in the dns suffixes of the lan adapter in your laptop.

I'm guessing that the following happens

From your PC at home you can ping the laptop....
When you ping your home PC from the laptop it resolves to the wrong domain suffix and is resoving to a random IP (internet range).....
if you manually ping your computerathome.domainathome.whatever that resolves ok......

Might be worth doing an ipconfig /flushdns but I guess you are fully shutting down not hibernating the laptop?

Just out of interest if you open up dns on your server, can you check if the laptop is registering correctly and if so what hostname it is registered as

Will try and help further if you can give me the info above.
 
That doesn't answer all the item I have asked you to check, if you can't be bother to reply then I'm afraid I don't have the time to help you further:rolleyes:
 
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