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DNS SUFFIX SEARCH LIST

Eric
Eric asked
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My question is conceptual one about DNS Suffix search list. Recently I was reading that DNS Suffix list seach is used for multi domain environment where computers can be member of multi-domains so that before client sends the dns queries to dns server , it can adds DNS suffix in order to netbios name of the computer.

I didn't understand this. First of all, how a computer can be a member of different domain simultaneously. In brief, why do we need to use DNS Suffix list search


Thanks in advance

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Commented:
Computer is member on one domain only but in the environment there are multiple domains.
For example:

servers.internal.mycompany.com
workstations.internal.mycompany.com

With servers in one domain and workstations in another (I know it usually it makes no sense in my scenario).
then you can add both domain names to DNS suffix search list and computers will "ask" both domains to find computer in DNS.
EricSystem Admin

Author

Commented:
I see,

then which point Primary DNS Suffix List gets added ?

For example, I am on the computer A in workstation.internal.mycompany.com domain and i am issuing a ping command against computer B which sits in server.internal.mycompany.com domain.

If I have DNS Suffix Search  list, lets say server.internal.mycompany.com;workstation.internal.mycompnay.com;external.mycompany.com

Then computerA will first try send the dns request to its DNS using ComputerB. Server.internal.mycompany.com and if it can't resolve it will try the ComputerB.servers.internal.mycompany.com and if it can't resolve it will try external and so on ?

Commented:
Your clinet will use only one DNS but it will ask him 3 times for all your domains. This DNS should resolve address you asked for or forward request and then reply to the client.
EricSystem Admin

Author

Commented:
So my understanding is that , client will add all DNS suffix search list one by one and send the DNS untill it resolves the one.

But at which point client will try to add the primary DNS suffix ? before or after trying DNS Suffix Search List or if it totaly ignore  the primary dns suffix, if it is configured with DNS Suffix Search list ?

Thx
Commented:
You understand this correctly. If you decide to enter suffix search list - primary suffix is not used until is entered as a list member.

You may look what actually hapens in nslookup utility. Start nslookup and type "set d2"
Then enter a hostname and look what client asks and what DNS server replies.