DNS for Domainers

[jacksonm]

A business owner should have a good understanding of those technologies which drive his core business. As a domainer, you are a business owner and your core business is domain names. DNS is the technology which drives your core business, thus you need to understand it at a moderate level. You do not need to be an expert at all the intricacies of DNS, but you do need to understand it better than the average Joe.

I see that many people here have almost no understanding of DNS, so I thought to try to help you obtain the required competence. I will explain it in such a way that it benefits you the most, while trying to protect you from confusion. As such, the explanations or diagrams may not be 100% technically correct in all cases, but they will drive the point home to you about what it is you need to know.

The first post in this series will start from the basics, along with a picture to help you understand.


DNS Hierarchy
----------------------------
DNS is a geographically distributed, hierarchical namespace. This sounds technical and confusing, but just view the picture and you will see that it's actually simple.

At the top of the namespace is the "root zone". The root zone contains entries with NS (nameserver) records for domains which are commonly referred to as "top level domains", or "extensions". Examples of these are: "global top level domains" aka "gTLD", as well as "country code top level domains" aka "ccTLD", and a smattering of other eclectic domains such as ".mil", ".edu", ".gov", etc. The NS records simply provide the IP addresses of of a domain's nameservers - the servers from which you can directly query records for said domain.

At the second level of the namespace are the nameservers for each of the domain entries in the root zone. These nameservers are owned by governments, organizations, and private companies. When you register a domain, an NS record for that domain will be entered into one of these nameservers.

At the third level of the namespace are the nameservers for individual domain names. These nameservers contain records for hostnames, hostname aliases, mail exchangers, reverse lookups, etc.

Here is a picture that will help you:




End of part 1.

[bramiozo]

Great initiative MJ, Seamo, can you sticky this please ?

[Rubber Duck]

Correct but it doesn't necessarily stop there. Privateers can use individual names to create their own namespace at the sub-domain level and I guess there is no specific reason why it has to end there.

[jacksonm]

Originally Posted by Rubber Duck

Correct but it doesn't necessarily stop there. Privateers can use individual names to create their own namespace at the sub-domain level and I guess there is no specific reason why it has to end there.

Yes, that's right, and good point. I can subdivide my own domain (and I have done so before) as such:


hel.fi.netauth.com
dus.de.netauth.com
sfo.us.netauth.com

etc..

With each of those locations managing their own DNS databases.

.

[Rubber Duck]

Yes, and under DNAMES any one of these could be presented to the World as a TLD, if you could only get ICANN to enter the appropriate alias into their future DNAME database.

As they say, the possibilities are endless, but the idea that is technology holding the boat up is bunk. It is not. Let the technical people loose and the Internet would change out of all recognition.

Originally Posted by jacksonm

Yes, that's right, and good point. I can subdivide my own domain (and I have done so before) as such:


hel.fi.netauth.com
dus.de.netauth.com
sfo.us.netauth.com

etc..

With each of those locations managing their own DNS databases.

.

[chineseidn]

Thanks, very useful. Looking forward to part 2

[mgrohan]

Great educational post, thanks for posting!

[htmlindex]

Nice post there Jackson, thanks for sharing.

[khurtsiya]

Thanks MJ!

Waiting part two

[Rubber Duck]

I have to admit, I am a bit stunned that so many of you seem not to have previously grasped these basics. It is not surprising that most discussions end up going nowhere!

[jacksonm]

Originally Posted by Rubber Duck

I have to admit, I am a bit stunned that so many of you seem not to have previously grasped these basics. It is not surprising that most discussions end up going nowhere!

DNS is complicated, but I am trying to break it down simple enough for all of you and I won't assume that you have any prior knowledge such as the fact that DNAME is a record type and not a protocol. :-)

I will eventually get around to showing you how these work in practice between the client (your workstation) and the resolvers.

Part 2 may have to wait until I return from my vacation this coming week in Amsterdam :-)

.

[bwhhisc]

Originally Posted by Rubber Duck

I have to admit, I am a bit stunned that so many of you seem not to have previously grasped these basics. It is not surprising that most discussions end up going nowhere!

You can count on one hand the people here that have depth and knowledge of all of the encompassing subjects that
get discussed here that include early IDN develpment starting with UTF5, and all of the documents and meetings that
probably go back to the mid 1990's from IDNA, GNSO, IETF, IANA, APNG, GNU, ICANN, MINC, etc. Plus add in DNAME,
NSRecords, aliasing, DNS knowledge, homonyms, homoglypyhs, spiffing, spoofing, etc. etc. You could make truly
understanding all this to the ninth degree damn near a full time occupation! So lighten up on the gang, just to have
more people here interested in IDN is a great thing and they will no doubt learn more from the 'pros' as time goes on.

[mdw]

That's a good post MJ. A lot of work to start a tutorial like this, but it's probably effort well spent.

Even techies don't necessarily know anything about DNS beyond what you've described already. Most just know enough to setup a local network, or they have dedicated servers that they add records to for subdomains or mail servers without realizing how anything really works.

Nothing wrong with that of course; most can get a server running, and see that bind is running, and unless there's a problem no need to ever learn how things work. But you're right it is a subject matter that IDNers can benefit from learning since it directly affects us all.

Kudos to ya!