domain propagation

8/3/2019 Domain Propagation

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DNS

Stands for "Domain Name System." The primary purpose of DNS is to keep Web surfers

sane. Without DNS, we would have to remember the IP address of every site we wanted to

visit, instead of just the domain name. DNS works in a client/server fashion.DNS is a hierarchical system. DNS organizes all registered names in a tree structure.

The reason the Domain Name System is used is because Web sites are actually located by

their IP addresses. For example, when you type in "http://www.google.com," the computer

doesn't immediately know that it should look for google's Web site. Instead, it sends a

request to the nearest DNS server, which finds the correct IP address for "google.com."

Your computer then attempts to connect to the server with that IP number. DNS is just

another one of the many features of the Internet that we take for granted.

There are three levels of domains are there:

Top level Domains

Second level Domains

Third level Domains (or) Local Domains

Top level Domain

A TLD (top-level domain) is the highest level of domain names in the root zone of the

DNS of the Internet.

For all domains in lower levels, it is the last part of an Internet domain name that follow

the final dot of a fully qualified domain name.

For example, in the domain name www.dnsknowledge.com, the top-level domain is com.

DNS server which keeps all root zone is called TLD name server.

One generally cannot purchase names at this level.


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Second level Domains

These are domains that organizations can purchase from any of numerous

accredited registrars.

In the Domain Name System (DNS) hierarchy, a second-level domain (SLD) is adomain that is directly below a top-level domain (TLD).

For example, in www.example.com, example is the second-level domain of

the .com TLD.

Second-level domains commonly refer to the organization that registered the domain

name with a domain name registrar.

Some domain name registries introduce a second-level hierarchy to a TLD that indicates

the type of organization intended to register an SLD under it.

For example, in the .uk namespace a college or other academic institution would registerunder the .ac.uk ccSLD, while companies would register under .co.uk.

A country code second-level domain (ccSLD) is a second-level domain to a country

code top-level domain.

A ccSLD may be reserved by the domain name registry for the registration of third-level

domains or assigned to a third party as a sub domain.

Many countries implement additional classes as well.

For example, the United Kingdom (uk) uses co.uk for commercial purposes and ac.uk for

academic registrants.

Third level Domains

Local domains like compnetworking.about.com are defined and administered by the

overall domain owner.

DNS supports additional tree levels as well. The period ('.') always separates each level

of the hierarchy in DNS.

If you need to further distinguish your second-level domain name, you can use a third-leveldomain name, such as "name.sampledomain.com." Typically a third-level domain name is usedto refer to different servers within different departments of a company.


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Third-level domains can be set up as:

y Domain alias to a target domainy Separate web hosting account

You can create a third-level domain using one of two different methods:

y By editing the A-record. Use this method if you want to point the domain name to aspecified IP address.

y By editing the CNAME record. Use this method if you want to point the domain name to

another domain name.

Note: The ability to edit DNS/MX records are available only to hosting customers.

Q. What is domain propagation?

Ans. Domain Propagation is the period of time, or delay, involved in sending your domains

address information to all the other name servers in the world. Name servers intentionally

keep track of addresses for domains in their memory for a specific period of time which is

defined by the administrator of the name server. This speeds up the process of looking up

an address for a domain name. Unfortunately this cached information also stays in the

name servers when it has been changed at the source of the original information

(the domains registrar).

Name servers refresh themselves from once an hour to once a day. Generally 2-3 days

time is a good estimate when a domains DNS information is changed at the domain

registrar, after which everyone in the world can see the change.

Q. Can I view my website even though my domains name servers havent propagated

yet?

Ans. Yes you can view your website even if your domais name servers havent propagated yet.

This is how you can access the domain -

http://IP-ADDRESS/~username/ (The IP address of the server you are hosted on will be


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provided to you upon sign-up.)

Generally a new domain name takes about 24 to 48 hours to propagate all over the world

wide internet. After the propagation across the Internet has completed, you will then be able

to use your domain name. The first sign that the propagation is nearing completion is when

your domain name shows unavailable when performing a WHOIS search. If you view the

WHOIS information provided and it shows you as the owner, then your domain name has

either completed propagation or will complete within the next day or two. When you yourself

are able to point your browser to yourdomain.com and see your web site as well as assuring

a few of your friends can do the same, then propagation has completed. To view the status

of your domain name check multiple WHOIS searches rather than just one.

How to check whether the domain was propagated or not?

First, you'll have to verify that you can "ping" your name servers as well as server aliases. If

your DNS host name is yourdomain.com, try pinging yourdomain.com to check if your DNS

zone has propagated correctly.

If you can able to see the output as the domain yourdomain.com is resolving into an IP, your

DNS zone has propagated properly.

Secondly, You can do telnet to your domain name with appropriate port number. If your domain

has already propagated then the port should listen to your domain

Example: telnet yourdomain.com 80 (where port 80 is for apache)

You can also test using dig & nslookup for linux and windows machines respectively.

For Linux machine: dig yourdomain.com

For Windows machines: nslookup yourdomain.com

Apart from the above steps, Some wonderful tools to watch propagation are located below:

http://www.dnsreport.com

http://www.dnsstuff.com

http://www.domainwhitepages.com

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