This is an area, which causes a great deal of confusion amongst both webmasters and end user clients.
Before we go any further, let's look at this quick analogy: DNS can be considered something similar to that of a phone book. When you move from one location to another, your last name stays the same, but your phone number may change. In order to point your name to the new phone number, you must contact the telephone service provider, which will assign you the new phone number. In addition, they update all directory information data basis to reflect you as pointing to this new phone number.
What is DNS?
DNS stands for "Domain Name Server." The domain name server acts like a large telephone directory in that it's the master database, which associates a domain name such as (http://www.mydomain.com) with the appropriate IP number. Consider the IP number something similar to a phone number: When someone calls http://www.h2hosting.com, your ISP looks at the DNS server, and asks "how do I contact h2hosting.com?" The DNS server responds, it can be found at: XXX.XXX.XXX.XXX. As the Internet understands it, this can be considered the phone number for the server, which houses the http://www.h2hosting.com web site.
Where are all of the DNS records kept?
This is slightly more complicated, but for the purpose of this overview, we'll try to keep it as general as possible. There are 2 basic places DNS records reside:
International Root name servers (13 exist throughout the world)
Your domain registrar, where your current DNS settings reside.
When you register/purchase your domain name on a particular "registrars name server", your DNS settings are kept on their server, and in most cases point your domain to the Name Server of your hosting provider. This Name Server is where the IP number (currently associated with your domain name) resides.
The entire hierarchy is somewhat involved, but in short, the world Root Name Servers can be considered the master listing of all DNS records, and there are currently 13 of them in the world.
These name servers are where all the master DNS records are kept. The DNS server of your ISP will typically query the Root Name Servers once every 24-hours. This is how they update all of their DNS tables, which in turn, resolve www requests to the IP number of the server they reside on.
Changing your DNS settings, so your domain points to your h2hosting.com account.
Your "Name Server Settings" must be updated to point to your account on h2hosting.com. You originally purchased your domain name from a registrar, and this registrar is where your current DNS settings reside. That is, unless you transferred your domain name to an alternate registrar, in which case, you would control your DNS settings from there.
The "Registrar" your domain resides on, communicates your 'current' DNS settings with the International Root name servers, which is turn share this information with ISP's, routers, and cache engines around the world. In essence, it's like a worldwide directory that other computers can refer to when they want to match a domain name with its associate IP number. This IP number is how the particular server your website resides on is located.
Accessing your domain manager.
Simply go to your domain registrars web site, and look around for links, which point to something like, domain manager, manage domain, or something of that administrative nature. In your welcoming email, you were sent DNS settings.
PLEASE READ YOUR WELCOME EMAIL IN ORDER TO FIND CORRECT DNS RECORDS.
Most of the newer registrars such as the (OPENSRS) based entities have turned this into a 5-minute process. You simply login to the registrar, select 'manage domain' and you'll be presented with an option to update your new DNS numbers. Contrary to popular belief, Network Solutions 'now' also provides an online interface to change these settings, so this process with them is no longer as complicated as it use to be, however it's still not as simple as the OPENSRS based systems. If your particular registrar 'does not' provide a domain manager of some type, then you'll need to send them a message requesting a change of DNS. This is an unlikely scenario, as most every registrar now allows you to manage your own domain settings from a web based interface.
Once you've accessed the "management interface" of your domain name, look for a setting, which says "change or manage DNS settings." In most cases, you can simply cut and paste the DNS settings we've sent you directly into the spaces, which correspond to your DNS management settings.
Propagation period - Understanding what happens during this time frame.
In short, patience is a virtue. Remember what we talked about earlier in this chapter regarding the shear size and scope of the worlds DNS system? In short, when you change your DNS settings, these new settings must propagate throughout the worlds DNS servers. It also means that every ISP Internet Service Provider), must update their DNS records to reflect these new changes, which in most cases, is done automatically every 24 hours, but not always however...
Where do the Root Name Servers receive their information from?
The Root Name Servers will query "domain registrars" several times a day. Domain registrars, being entities such as Network Solutions, and the newer OPENSRS based systems. The Root Name Servers will gather this information from the many registrars now in existence, and update their master records accordingly. Now your ISP must access the Root Name Servers, and update their DNS records, which reside on their 'local' DNS server. This process is fully automated and most ISP's will check the Root Name Servers for updates every 24- hours. Beware however, that some lame ISP's will delay this process for as much as 2 to 4 days in some cases. If that happens, it will no doubt cause additional confusion, as everyone else will be reaching your new account on our servers except you. This is because your ISP has not updated their DNS records, and or have not cleared their DNS cache, which means they'll still be pointing your domain name to your old server.
If it's a new domain name you've registered, then you'll receive a blank "Site Not Found Page."
DNS Cache and your ISP.
There is also the issue of DNS cache, which is something we won't go into great detail about here, but here's the short version. Every time you access a site from your ISP, they cache the URL, as well as its associated IP number. If their network is properly setup, these DNS cache records should "Expire" at least every 24-hours. If they did not (which is often the case), you'll experience this: You enter your http://www.mydomain.com URL, and it keeps taking you back to your old server account.
In a large number of cases, it's the result of an ISP who "Did Not" configure their servers to "Expire" the DNS cache records at the appropriate intervals. Unfortunately, this adds additional confusion to their clients, and especially the ones whom are trying to point their domain name to a new server. Yes, it will make you want to scream sometimes, however if you understand whom is actually at fault, then you'll know who to scream at :)
The DNS propagation process is not limited to ISP's!
Just when you thought you had it all figured out! Unfortunately, there's more. The Internet itself must update/clear its DNS cache as well. When we say the Internet, we mean the numerous intermediate "points of access" you're routed through before reaching your final destination. For the most part, these intermediate points of access consist of "Internet Routers" and "Internet Caching Engines." These too, maintain their own DNS cache, which assists them in routing traffic/resolving URL's to the correct destination IP's. Don't worry though, as Internet routers are usually faster at clearing their DNS cache than ISP's are.
What to expect during this 1 to 2 day propagation period.
In most cases, the propagation process will take at least 24 hours to complete. The first thing that happens is the "World Root Name Servers" will check all of the various "Domain registrars for updates. Ok, so now the Root Name Servers have done their job. The rest of it is up to the many ISP providers who "should be" updating their DNS records (at least every 24 hours), but a number of them will not.
Side effects that can be expected during the propagation time frame.
It's perfectly normal for strange things to happen within the 48-hour propagation period, but sometimes longer. While we could provide a full list of all the anomalies that can occur during the DNS propagation period, we'll stick to some of the most common scenarios that most people experience:
HELP! My friends can reach my new site, but I'm still being directed to the OLD ONE!
This is a class case of your friends ISP (who did update their DNS records), but yours unfortunately did not. As a result, your ISP is still pointing your domain name to the old DNS record, which is your old hosting account. Wait a couple of more days, and if it appears that everyone but you can access your new account, then contact your ISP and tell them to expire their old DNS cache records.
http://www.mydomain.com was taking me to my new h2hosting.com account just a minute ago, but when I try it now, I'm being taken back to my old hosting account - what's up with this?
In all likelihood, your ISP may be in the process of clearing their DNS cache, and or updating their local DNS server records. During this small interval, it's normal to fluctuate between the new and old web site, as the old DNS records may not have completely expired from their cache yet. Give it another several hours and it should be fine.
My new site comes up for me, but my friends are being directed to my old one!
Break out the coffee and donuts, and consider yourself lucky. Your ISP is on the ball and updates DNS records/ clears DNS cache in short regular intervals. Your friends may be using an ISP, which is not as fast, and or efficient at doing so. The only remedy for this is time. Eventually, the other ISP's DNS cache will expire and be replaced with the updated DNS records.
What's going on with my email? When I try to access it, I receive a "host does not exist" or a "cannot authenticate" error message.
This can happen for a number of reasons, but in most cases, it's because your new DNS records have not fully completed the propagation process yet. Consequently, you may be trying to access your old
email account on your "old server", which you may have already cancelled, or it's in a state of DNS flux, which means it points to the new server one moment, and the next, points back to the old server.
Give it some more time and it will eventually settle down. In the meantime, consider accessing email from your account using the WebMail based reader. If your domain has not propagated as of yet, you can access your email account via WebMail with your IP number. Example: http://220.127.116.114/webmail/ This will allow you to access your default mailbox on your account. Replace the IP number with the one we sent you.
Microsoft FrontPage will not accept a Username and Password, or displays the error message (FrontPage Extensions Are Not Installed).
While you should be able to access FrontPage with your associated IP number (until your domain is resolving to our servers), this is not always the case. FrontPage can behave in a number of different
ways depending on which direction the wind is blowing. In some cases, it will allow you to initiate an upload session, but upon asking for your Username and Password, will not recognize them. If this happens, the best thing to do is wait until your domain name is answering to our servers. One thing we know for sure, is FrontPage will work without much of a problem if you're using the full www.mydomain.com URL to manage your site with. Feel free to try it with your IP, but we cannot guarantee it will work.
It's been over a week. Everybody else can access my new site except me!
Was your domain originally hosted by your ISP? If so, they may not have deleted this entry in their DNS files. This results in you, and or anyone else accessing the net from this "particular ISP" being directed to your old web site on their servers. A number of ISP's forget this small detail, which can result in weeks of utter confusion and frustration. If this is happening to you, contact your ISP and make sure they've made the necessary changes to their DNS records.
Checking your DNS update status (outside of your ISP)
In the event you're becoming impatient, and or are wondering if the rest of the world outside of your ISP can access your new site, you can proxy yourself to another network and test it there. In many cases, you'll be surprised to see your site responding perfectly, yet when you attempt it directly from your ISP's servers, it does not exist.
There are several services, which allow anonymous surfing across the net. While this is not the intent here, they can be used for trouble shooting domain resolution problems. How? Because they proxy you through their network, which means your URL requests are controlled by "their" DNS cache records. These services update/ expire their DNS cache far more often than ISP's, which makes them well suited for testing your domain name through a network, which operates with the latest DNS updates across the web.
To run this check, you can try accessing your site through http://www.dnsreport.com
This site will allow you to enter a URL, and proxy your request through their servers. If your site is
accessible from these servers, then chances are, your ISP has yet to expire their old DNS cache records.
Working on your account during the DNS propagation period
You can still work on your new account until your domain name finds it way to our servers using your "IP Number", which was included in your welcoming email. Your IP number is how your new domain will be identified on our servers. Using it at this point will provide a means for you to access your account,
as well as test your new site by using something like http:// 18.104.22.168/ (obviously you'd replace it with the IP number we sent you).
One easy way to check and see if your domain is answering to our servers yet, is to create a file called "test.html" and place it in your web directory. Keep checking the URL http://www.yourdomain.com/test.html and see if it works. When it does, you'll know your domain name
is answering to your account on "our servers", and has been officially transferred.