Internet computers are setup to ultimately query the "root servers" when they need to translate a "host name" such as www.fibrewood.com to a numeric IP address. (Typical ADSL or cable modem user is setup to query their ISP's DNS servers, but the ISP's DNS servers will eventually point to the 13 "root servers").

The "root servers" (click here for more information about root servers) only tell your ISP's DNS servers to query (geeks call this "delegate") the appropriate "top level DNS name servers". Every country and each recognized "administrative group" operates their own "top level DNS name servers".

For example,   .com  .net  .org  .ca  .uk  .edu  .au  .de  .mil  .int  .us  .biz  .nz  .hk  .cn  .ch .tv 
are separate administrative groups. They have their own "top level DNS name servers".

When you register with a domain registrar, the registrar sends some information to the "top level DNS name servers". The information stored on the "top level DNS name servers" is:
your domain name, two DNS servers of your choice, and the IP addresses of your two DNS servers.

Many overpriced, brain-dead (but very famous) domain registrars do not allow you to choose your preferred DNS servers for your domain, you are forced to use their DNS servers or DNS servers. If that is the case, find another domain registrar that is more user-friendly.

A minimum of two DNS servers is needed for each domain for fault tolerant.

The "top level DNS name servers" tell your ISP's DNS servers to query the DNS name servers that you have chosen at time of registration. On these DNS name servers, they store information about your domain such as the numeric IP address of your web server (or a server that does web forwarding) and the numeric IP addresses of email server(s) that accepts emails for your domain.

Once the IP address is found, it is returned to the PC that made the query, the Internet user will be able to make a http request to your web server's actual numeric IP address.

DNS servers - how they work.

When an Internet user wants to find the IP address of, e.g., www.fibrewood.com his/her PC issues a DNS query to ask for the IP address of www.fibrewood.com  In geeky terms, this translates to "issues an A-record DNS query". This query goes to the user ISP's DNS server, the ISP's DNS server makes an "A" query to one of the "root servers".

The "root server" determines that it is a ".com" query, it returns the IP addresses of the "top level DNS (geeks call it TLD) name servers" responsible for the ".com" domain. See this list.

Some more confusing, geeky terminology: the "top level DNS name servers" for .com and .net are also known as generic top level domains servers, or gTLD. See this list.

Let's assume that company fibrewood registered its domain name with www.godaddy.com , during the registration process, fibrewood chose to use godaddy's parked DNS servers.

Let's further assume that fibrewood already has a small web server with a static or quasi static IP address that is "accessible" from the outside world. (they have a user-friendly cable modem or ADSL company)

The "A-record DNS query" sent to the "top level domain servers" returns the IP address of the  DNS name server ( park13.secureserver.net ). Your ISP's DNS server then issue another query to park13.secureserver.net,  an IP address is retured, eventually that IP address returns back to the Internet user desktop. The Internet user's PC then issue a real http request to the IP address.

For more fun in learning the mysterious DNS system and finding out more about (digging into) these elusive domain name servers, and their sneaky (clever) delegation system and how they control the world, and suck up tons of money from the world for doing practically nothing, please see this page. The DNS system is the biggest money scam mechanism in human history, operated on a global scale.

Web Hosting and Web forwarding

See this diagram on how web hosting works. In practice, the web hosting company probably wants fibrewood to use web hosting company's DNS servers. Hence "A-record DNS query" for www.fibrewood.com goes to the web hosting company's DNS servers.

The drawback of this scheme is that fibrewood may have to add email hosting services (with the same hosting company) because DNS servers also control how emails are being handled.

Suppose fibrewood decides that it wants to use the existing web space already included by its ISP. Fibrewood chooses godaddy's park.secureserver.net as the DNS servers. Fibrewood goes to godaddy admin control panel to add a "web forward or domain forward" feature. The result is that the IP address of www.fibrewood.com is now pointing to a web forwarder at godaddy, but that web forwarder has special code that re-directs all the http requests to fibrewood's ISP actual web server. See this diagram.

Another option for fibrewood is to have a "static IP" address and run its own web server. Fibrewood uses park.secureserver.net DNS server to set the IP address of www.fibrewood.com to the the IP address of the web server.

Note that web forwarding requires more that just the DNS servers, it requires a "web server" or "web forwarder" that accepts incoming http calls, makes the interpretation, and redirects the calls to another web server.

Email Hosting and Email forwarding

Fibrewood can add email hosting service with its web hosting company, in that case, the DNS servers should be the web hosting company's DNS servers.

Fibrewood can use godaddy as the DNS servers for emails (extra costs). Fibrewood goes to godaddy domain control panel" to add a "email forwarding" feature. The result is that the IP address for emails to @fibrewood.com will point to a email server at godaddy, but that email server has special code that forwards emails to a email address of Fibrewood's choice. See this diagram.

Another option for fibrewood is to have a "static IP" address with its ISP and run its own email server. Fibrewood uses park.secursever.net as the DNS servers. Fibrewood sets up an MX-record and points to the IP address of its own email server. (Another geeky thing: when email is involved, MX-record is used instead of A-record)

email forwarding requires more that just the DNS server, it requires a "email server" that accepts incoming calls, makes the interpretation, and forwards the mails to another email server.

Service Overlaps - truly overwhelming

There is a massive overlap of services between domain registrars, ISP, DNS services, web/mail hosting companies, and web/mail forwarding services. All big-name expensive domain registrar also provide you with "free" DNS servers, they also run web and email hosting services. Some company only provides DNS service.

Nearly all web hosting companies include DNS service. ADSL or Cable modem ISP generally provides some limited web space and limited email space. Some companies do web forwarding, some don't, some charge extra for it.

If you separate out the different functional blocks of the DNS system, i.e., how the information flows when someone types  www.fibrewood.com and sends email to  info@fibrewood.com  , you can shop around smartly and find the best functional blocks at the lowest overall cost and achieve best results in flexibility in how to use your domain name.

For novice domain owners, use your ISP's web space as your web servers, use godaddy.com parked DNS servers to "domain forward" to your ISP's web space.

For expert domain owners with static, unblocked IP address, build your own web servers and email servers and have godaddy server point the "A records" and "MX record" to these servers. Often a web server (apache) and email server (exim) are in the same Linux box.

Many brain dead businesses are still paying $35 a year for registration where you can get one for less than $10 from many places.

References:

RFC1034 Domain Names - Concepts and Facilities
RFC1035 Domain Names - Implementation and Specification

Disclaimer

© 2002-2009 Nicholas Fong, e-mail

Last revised: December 12, 2008