DNS at a Glance

[Hope]

DNS – Domain Name System

A Brief History

A long time ago in a government not so far away … Ok, so it wasn’t that long ago unless you are talking Internet years. Then it was the dark ages or more appropriately the monochrome ages. The ARPANET (Advanced Research Projects Agency) was the Beta of what we know as the Internet. When the ARPANET was running there were a lot fewer computers connected at that time.  Hosts.txt files were used to navigate the ARPANET.

TCP/IP (Transmission Control Protocol/Internet Protocol) was the beginning of what we know today as the Internet. With the new protocol came more computers and more people using them. The Hosts.txt files became extremely inefficient. The biggest problems were traffic, name collisions and consistency. It became necessary for a global database that could route traffic. In 1984 the architecture for what is now DNS was designed. It is a global database of DNS records.

What is a DNS record?

Since we are trained from a young age to identify names we use names instead of numbers. This helps us remember how to find a site. It is much easier to remember SEOAnalysis.com than it is to remember 66.113.163.187.

Computers on the other hand don’t really care about names. They would work just find if everything was numbers. Remember back to the Dark Ages of computers and everything was binary (1s and 0s). IP is a series of numbers to identify each computer. It is a logical way of seeing things for computers.

The domain names and the IP addresses needed a common translation process. Since there are thousands upon thousands of computers attached to the Internet, it needed to be in one location.

DNS records are located on DNS servers. They translate the domain name to the IP for every computer. It is done with a Database that is queried all the time. There are thousands of DNS servers across the Internet to support the constant use.

What are the different parts of DNS?

A Record – This is the part that translates the domain name to the IP.
CNAME – This is a domain name alias.
To mask this, CNAME-records can be used to give a single computer multiple names (aliases).
For example the computer "computer1.xyz.com" may be both a web-server and an ftp-server, so two CNAME-records are defined:
"www.xyz.com" = "computer1.xyz.com" and "ftp.xyz.com" = "computer1.xyz.com".
MX-Record – This record specifically points to your email server.

[Andy]

Thanks Hope for de-mystifying this subject 

Some people will have access to a DNS control panel for their domain name and could maybe set up subdomains for their domain name.

I wonder how easy it is to do? Then they could have something like blog.domain.com as well as just www.domain.com for example so they don't need to register a new domain for a new dimension to their web site empire 

[Hope]

Subdomains are usually done with A Records.

People need to remember that DNS is only half of the job. The server needs to be configured to accept the domain name. I will get on that in a later post.

[carpmad]

cheers for that Hope
i never realy knew what it was other than a few numbers
when i had to set my modem up the other week i had to put the dns in, its the first time ive ever had to deal with it so its nice to find out what it actualy is used for

[Andy]

I had a headache on this subject today which I think I just resolved and now I am refreshed (bad joke for some) 

Some dude bought a DOT COM and a DOT CO DOT UK name for a site I am making for them. So now I have to think about what the site will be i.e. DOT COM or DOT UK I reached the decision easily since DOT UK involves some stupid tag that has to be changed by the domain registrar. With DOT COMs, only the nameserver settings need to be changed. The problem with the Tag change is that it tells your customer that you are selling them hosting that they can get cheaper by going direct rather than via a reseller like me. So there is no way I am setting this up with a DOT UK primary domain name.

If they hadn't registered the DOT UK name they could have got it for free anyway with the hosting.

So, I will tell them what the name servers are to change in their DOT COM DNS control panel and ask them to forward (301 redirect) the DOT UK name. But whatever name they use to view the site it will show as a DOT COM in the browser.

I think this is the way to go here isn't it?

I was thinking about if there was a way to configure the CNAME setting in the CO UK control panel so it shows a DOT CO DOT UK host name in the browser but I don't think it works like that, does it?

But even if it did it would look like 2 sites with the same content and maybe get hit with a duplicate content penalty.

A further trick I have up my sleeve is to detect which domain name was used to access the site and use that information for a little simple geo-targetting of the visitor experience such as "hello" or "howdy" being shown  - only a stupid example.

Seriously, anyone out there with direct experience of hosting a multiple domain name site which is catering for various nationality visitors may be able to offer some tips here.

[donecweb]

The only consideration I see is if the site is for stuff that would be for a local community then if the community was in the UK then the UK site might be better for them.

[Andy]

The problems I see are the currency that the product is priced in, the location of the product fulfillment center and the locality of people providing testimonials. But this is diverging from the questions I posed in my post.

[franky]

It's always better to have the host in your own country.

[SensoVision]

It's always better to have the host in your own country.

Agree, but only if most of your visitors also country specific, if you have worldwide traffic it's may not be good idea.

[Andy]

It's best to host in the USA if most visitors are from that area. Then pages will load fastest for the locals and the IP address of the site will be geo located in the correct region for best SEO.

[grotesk]

Is DC location influence the speed of the web site?

[YMCA]

Not exactly, it's rather the network your dc uses that influences the speed, location may be important only if you want your site to ranl top in the local se lists or want a host to be in your vicinity.

[Teflon]

I have been dabbling in this DNS malarky today surprisingly straightforward once you get the hang of it.

[Andy]

I think that the speed of your website is mostly governed by the size of the files comprising the web pages. The bottleneck for bandwidth is usually at the customer end.

If you want a fast site, keep your image sizes small. 1 picture may be 100KB but an article may only be 10KB.

Pinging some of my sites I get a round trip (around the globe) connection time of up to 280ms average (the blink of an eye), but downloading web pages takes several seconds.

To ping a site, go to the command prompt (Run -> cmd in Windows XP) and enter: ping www.yoursite.com This gives you some round-trip timings for resolving your domain name and getting a response from the web server.

[donecweb]

I think that the speed of your website is mostly governed by the size of the files comprising the web pages. The bottleneck for bandwidth is usually at the customer end.

I think the biggest thing that is slowing down site loading is advertising. If there are way too many ads or complicated ads on websites then the server has to go fetch the information for those ads and pars them. This takes time and is the reason if you watch the status bar you see waiting for such things as Google.xxxx. Also it seems Sites that use Google Analytics are being slowed down by that a lot be cause I keep seeing waiting for Google Analytics.