Comments on: how DNS works

By: drmikec

drmikec — Wed, 22 Dec 2004 10:24:20 +0000

There was good advice in a previous reply - if you don't know exactly what you're doing, you can get in over your head really quickly. Buy the O'Reilly book and study it. There really are no shortcuts. There have been pointers for you on how to do DNS on Windows; if you're considering Linux, check out this link: http://www.tldp.org/HOWTO/DNS-HOWTO.html. This describes implementing BIND (named), which is the defacto standard for the internet. More specific information about exactly what you are trying to do will allow us to give more specific answers.

By: dwiebesick

dwiebesick — Wed, 22 Dec 2004 09:55:52 +0000

DNS is too complex for a simple answer. Try some of these training llinks.

http://www.microsoft.com/windows2000/techinfo/training/w2kdnsts.asp
http://www.microsoft.com/Windows2000/technologies/communications/dns/default.asp
I especially recommend the following for someone new to DNS as it is a full training course on CD that you can build from an ISO image.
http://support.microsoft.com/default.aspx?scid=kb;en-us;330511
Just download and build the CD.

If you are thinking of hosting or developing a DNS that is exposed to the public internet, DON’t, you do not have the knowledge, experience and skills required. This information is for setting up a DNS for an internal (intranet) network.

Let us know more what your exact enviroment you are trying to create.

By: petermac

petermac — Wed, 22 Dec 2004 09:06:07 +0000

You will need to configure your server to run DNS, done from the network settings (Advanced), Once DNS is installed you will have option to manage in Administrative tools. If you only want to run Internal DNS this is all that is required. If you want to support external DNS queries you will need an external IP address for the server, and will need to have a registered Domain Name where the DNS SOA entry is pointed to this IP address.
Is this sort of information you are looking for, can clarify if it is.

By: xevier

xevier — Tue, 21 Dec 2004 23:20:25 +0000

thanks to all of you for your kind replies,
but this much i knew .what i mean is that if suppose i wish to configure a DNS server of my own where should i start from.and after configuration how can i access and maintain my server.can you please help me?

By: drmikec

drmikec — Tue, 21 Dec 2004 18:10:45 +0000

Xevier,

I’m going to go a little simpler than the previous responses, although they were accurate. DNS is a very simple concept that is very complex in execution.

The internet doesn’t work with names, it works with numbers (IP addresses). DNS is a system to translate names to numbers. It begins when you register a domain name. You have to declare an authoritative name server (AS) for that domain. It will be responsible for knowing the IP addresses of all the named machines in that domain. The AS information is provided by the domain registrar to the root name servers, so, at last resort, a DNS request can go to the root servers and find an AS reference.

A domain name server is a machine on your network running BIND (named) or another name service or daemon. It is configured to know the IP address of all the named machines on your network, along with reverse lookups and root server information. When they are going out of your network, all the machines on your network will ask this machine for a name->address translation, and it will go out as far as necessary (even to the root servers) to find an authoritative source and return the IP address to the requesting machine. Also, it will be available to machines outside your network for when they need a name->address translation for one of your machines. As it collects the information, it will cache it in memory so it doesn’t have to ask every time. The configuration files include information about how long a lookup is valid, so it will only keep the info in the cache for that amount of time.

That, in a nutshell, is DNS. It is really much more complex than this explanation, but the concept is simple.

HTH.

-Mike

By: freejack

freejack — Tue, 21 Dec 2004 12:06:11 +0000

O’Reilly has an excellent book that not only explains DNS operation but also how to configure DNS servers, and a wealth of other information besides. The book is DNS and BIND, 4th Edition, ISBN number 0-596-00158-4. I’d recommend checking bookpool.com for the best price.

By: petermac

petermac — Tue, 21 Dec 2004 07:25:40 +0000

Last part of your question – How to use.
Not sure how complex an answer you want, but simple details as follows.
Two normal methods are :- Automatic discovery – default on all windows systems, requires a DHCP server supplying details of the DNS server to use – This is method used by all dialup ISP connections, and also by most systems running under a windows domain. The IP address of the DNS server is supplied at the same time as the IP address for your system.
You can also set your default DNS servers manually in the TCP properties settings along with the IP address. Remember your system must be able to route to this server, and vice versa.

By: duduspace

duduspace — Tue, 21 Dec 2004 03:10:29 +0000

DNS is one of the backbone services without which the internet would not work.
I will not try to explain DNS whithin this reply because you seem to want a detailed explanation of the service along with implementation and configuration issues.
I will however try to give you what I consider to be a roadmap towards approaching the service.
You can start with any study material on Network + i.e. Sybex, Coriolis e.t.c.(any good book will definitely have a chapter covering the basics of DNS)
You can from there learn more about Windows 2000 DNS (which comes with virtually all Windows Servers I know) by picking up any study material covering Windows Network infrastructure Implementation and Administration (They will definitely have one or more chapters on the Windows DNS service. I used Windows 2000 but you might want to consider Windows 2003 to be current)
There are other advanced study guides dealing with DNS as a topic which you might also want to drill down into Any Linux +/RHCE study guide should also discuss BIND though I have not really followed that route.
Basically DNS is a name resolving service that transparently converts names like http://www.hotmail.com to ip addresses.