Links



The images above, are actual Image Links, and are click-able. Use them to navigate to the sites indicated!

Wednesday, 28 April 2010

What is a Cname? How do I add it to my Domain DNS ?



After you purchase your Custom Domain, and once you receive your GoDaddy Registration Confirmation Email, from Google Apps, you set-up your Admin account. Then you will have access to the Google Apps Control Panel.

There, you can monitor the status of your services, manage your user accounts and email lists, create web pages, and customize the interface and services to your organization's needs. Through the Control Panel, you can also view and edit all your DNS Settings, update your WHO IS information, and renew your Domain, before it expires. Among lots of other things, you use this Control Panel to add Aname (host) and Cname (alias) records, to your Domain.


The Domain Naming System (DNS) is a very deep, complex subject, best left to the experts, but a simple analogy may be to say that it basically provides your Internet address. Your domain name is translated into an Internet Protocol, or IP address, because computers understand numbers better than alphabetical letters, which we use to make our URLs.

A URL is constructed a certain way - in levels, like nearly everything else on a computer. After the Hypertext Transfer Protocol, the component parts, concatenated by a 'dot' (.) after each part, in the case of my blog's URL, are:-

  • The third-level, or Subdomain, domain - eg: www., or blogging.
  • The second-level, or Root domain - eg:robertosblogs
  • The first-level, or Top-level, domain name - eg:.net


... and your Domain is, in turn, hosted, either by GoDaddy, or hundreds of other companies called FTPs.


So, what is a Cname, or Alias?


Without delving too deeply, a Cname, also known as Canonical name, is the properly denoted host name of a computer. A Cname specifies an alias, or nickname, for a canonical host name record - a computer, in a Domain Naming System, (DNS), record.

Its responsibility is to identify the location(s) of a site(s) on the internet - particularly on the Web.


Any computer can be the target of any number of Cnames, but a separate Cname record must be defined for the domain which sources each alias. For each Cname record, you provide an alias (the source), and a host (the target). For instance, in a URL such as blogging.robertosblogs.net , the subdomain, blogging., is written before the domain name root, robertosblogs.net. Another host could be blogging. / www.blogging. which I use for this blog. That's one of the best reasons to have a Cname, because there could be many source Domains resolving to the one target.

Note: - Currently, if you publishing your Blogger blog to a non-root host in your Domain, it is recommended that you record, what is sometimes called your naked domain, as well as your www. alias, so that you have a symmetrical pair of hosts defined. Publish to the www. alias, not the naked alias.

The reason for this is that currently, re-direction is asymmetrical. Hopefully, this will be a temporary situation!

To confuse you even more, in the following images, my subdomains, or aliases, point to ghs.google.com. Why would I use ghs.google.com as the Points to Host Name, when the add a Cname record (see: step 9. image below) wizard, suggests otherwise? Well, to try and keep it simple, ghs.google.com is the central core/DNS array, so to speak, of a multi-tiered server system, with many filters. Most ISPs around the world will cache copies of ghs.google.com for speed of return (TTL)...

- One computer, called Son, talks to another computer, called Mum, and says; " What's Bob's address?" Mum says; "I don't know. Go ask your father, he'll know!" Well, ghs.google.com is the father - but, on the way to ask his father, someone, maybe a sister, gives Son the address. So, there's less strain put on Dad and he doesn't get overworked (how it should be). He planned it that way, too, 'cause we Dad's are smart! It's called referral. To speed-up the process of finding out your address, your ISP will have a surrogate picture of the 'father', on hand, to ask for the address. That speeds everything up.



So what are the steps to add a Cname record?

Step 1. Sign in to your Google Apps account




Step 2. Select, and click on, domain names.




Step 3. Select and click on Advanced DNS Settings




Step 4. Take a note of your Sign-in name (generally, a number), and highlight and copy the Password. The reason for this is that it works better to do it that way.




Step 5. Using the information from the previous screen, Sign-in to the Domain Control Center




Step 6. Once in the Domain Manager, click on your Domain Name link




Step 7. Click on Total DNS Control (nothing else)




Step 8. This screen is where you can add a Cname record, as indicated. Don't change anything else!




Step 9. Add your (subdomain) alias name, eg: blogging. or www.blogging. Also, you have to complete the Points to Host Name section, and the TTL (explained above).






(Back to above text)

Step 10. Check your entries. If all OK - log-out.





Last, but not least, the Aname record - what is it?

The 'A' record, or Aname, points your Domain to an IP address. You would change this ONLY if you wanted to point your website to a different IP. You use an 'A' record to define the IP addresses of the 4 Google Apps DNS proxy servers, when you're defining the domain root, and pairing it with the www. alias.

An MX record is only for email, and is changed ONLY if you want to re-route your email.


TOP

1 comment:

Adol said...

Now only I have got a brief explanation about cname. Already I know the definition of cname. Now I am clear. Buy domain India