Most reasonably technical Internet users have a pretty good idea what DNS is, but what actually happens when you look up a domain name is not always so clear. For those of you who are a bit uncertain of how it works (or just like geeky server charts), we found an excellent picture describing the chain of events of a DNS lookup.

The image below is from Verisign, and to simplify matters a bit it ignores the effect of caching (normally results are cached at various points along the chain):

Image source: Verisign Domain Name Industry Brief, June 2007 (PDF), last page.

The chain of events to get the IP address for www.abc.com:

First your computer queries the name server (DNS server) it is set up to use. This is the recursive name server shown above.

The name server doesn’t know the IP address for www.abc.com, so it will start the following chain of queries before it can report back the IP address to your computer (the numbers below correspond to the numbers in the image).

1. Query the Internet root servers to get the name servers for the .com TLD.
2. Query the .com TLD name servers to get the authoritative name servers for abc.com.
3. Query the authoritative name servers for abc.com to finally get the IP address for the host www.abc.com, then return that IP address to your computer.
4. Done! Now that your computer has the IP address for www.abc.com, it can access that host.

This won’t be news to some of you, but you have to admit it’s a good picture! Definitely worth sharing.

Perl has been around since 1987 and became an early darling of web developers. These days, however, you don’t hear much about Perl. Everyone seems to be talking about trendier languages like PHP, Python and Ruby, with Perl left in the back as a neglected, not-so-hip cousin.

That might lead you to think that Perl is dying, but as it turns out, it’s still used by plenty of websites out there, including some pretty big hitters.

Here are some of the more popular sites that use Perl extensively today.

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In this post Twitter enthusiast Garin Kilpatrick shares his tips on effective ways to get more followers.

It is hard to put a price on a Twitter follower but the host of The Price is Right, Drew Carey, is offering to donate $1 to cancer research for every new follower he receives this year. The following eight tips will enable you to make the most out of your tweets and help you connect with as many followers as possible.

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Web design carries with it certain challenges that don’t exist in print design. Perhaps the most obvious is that in print design, whether you print your own work or have it printed by a professional, you know what your work is going to look like before your customer sees it.

Web designers don’t have this luxury. There’s always the chance that something, or maybe many things, won’t look or behave the same from browser to browser and from operating system to operating system. It’s easy to make mistakes that can make your website appear strange or annoying to a lot of website visitors.

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This April 1st the guys at Wired Magazine put together a great April Fools’ joke: A dedicated mobile device for Twitter dubbed the Wingman.

Check out this video introduction to the (then) totally fake device.

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Looking back on Android’s first year on the market, there’s no denying that things have been rocky for Google’s ambitious mobile platform. There was little hardware diversity for the better part of the year, and with the hype surrounding the release of the Palm Pre, Android seemed almost instantly dated. For all of its initial hype, the platform never really seemed like much of a threat to the iPhone, and in many ways it was barely competing. It seemed as if Android was going to celebrate its first birthday merely running on the fumes of excitement from its launch.

The announcement of the Motorola Droid’s upcoming release on Verizon’s formidable 3G network changed all of that.

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