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How DNS suffix search list works ?

Question

Sunday, February 13, 2011 6:14 AM | 1 vote

Hi,

I just wondering what is the process of DNS host name resolution. For exemple:

 

My pc name is: MyPC in domain "domain1.com"

I ping or use nslookup cmd to get IP adr of pc host name: PCx

In my Windows DNS server (Static DNS, not AD integrated) I have:

 

PCx.domain1.com A 192.168.1.1

PCx.domain2.com A 192.168.1.2

PCx.domain3.com A 192.168.1.3

 

My question is what is the order of name resolution? In what case one domaine will answer instead of the others for the same host name?

 

 

All replies (7)

Sunday, February 13, 2011 6:57 AM ✅Answered

In simplification the evaluation is done from right to left. So first DNS will search if it hosts Forward Lookup Zone fo domain1.com if the Forward Lookup Zone does exist it will return ip from A record of MyPC. If DNS does not host FLZ for this domain it will pass the request to other DNS server (either configured via forwards or root hints)With kind regards
Krystian Zieja
http://www.projectnenvision.com
Follow me on twitter
My Blog


Sunday, February 13, 2011 8:12 AM ✅Answered

No you cannot assume that (acctually in most cases you can but to be precise). In your network configuration (example below) there is DNS Suffix Search List, if you ping from MyPC which has DNS Suffix Search List domain1.com, DNS server will try to find PCx.domain1.com so it will evaluate FLZ for domain1.com. If record of type A of PCx is not found in that domain (domain1.com) DNS server will not search other FLZ being hosted on that server

C:\Users\krystian.zieja>ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : w7
   Primary Dns Suffix  . . . . . . . : projectenvision.com
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : projectenvision.com

With kind regards
Krystian Zieja
http://www.projectnenvision.com
Follow me on twitter
My Blog


Monday, February 14, 2011 2:22 AM ✅Answered | 1 vote

Hi Samata,

I realized Krystian did a nice job answering your questions. I thought to provide more information on suffixes as an additional resource, as well as if anyone is searching the Technet forums for information on suffixes. I hope it's helpful for anyone reading it.

Configuring DNS Search Suffixes
http://msmvps.com/blogs/acefekay/archive/2011/02/12/configuring-dns-search-suffixes.aspx

Ace

Ace Fekay
MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services

This posting is provided AS-IS with no warranties or guarantees and confers no rights.


Sunday, February 13, 2011 7:05 AM

As I said I ping PCx.

Can we suppose that PCx.domain1.com will send his IP first because I ping from MyPC which is in domain domain1.com? If yes, if I delete the record "PCx.domain1.com A 192.168.1.1" does it goes to the second domain for getting the IP: PCx.domain2.com A 192.168.1.2?


Sunday, February 13, 2011 8:12 PM

Ok I see thank you so much for your help!


Wednesday, February 16, 2011 1:19 PM

Good thank you for the info!


Wednesday, February 16, 2011 7:30 PM

You are welcome!

Ace

Ace Fekay
MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services

This posting is provided AS-IS with no warranties or guarantees and confers no rights.