Wise Women List Archive File

What is a Virtual Domain?

Question:

Hi WiseWomen,

Can someone please explain, in regular layperson-speak, the difference between "virtual" domain hosting and the regular kind? I'm pretty ignorant when it comes to networking matters, so any enlightenment is appreciated.


Hi

This is my understanding (recommend apply cup of coffee before reading :-)

HOW DOMAINS WORK...

As I understand it domain names were set up as a human interface to a system of numbering computers/webspaces - because people like words, and computers like numbers. In the old days (5 years ago or more) there was pretty much a 1:1 relationship between webspaces and IP Numbers (IP stands for something like Internet Protocol - is definitly *not* intellectual property in this context).

IP numbers look like 101.121.143.56 (for example)

domain names are "name.com" or "name.co.nz" (note that www is not part of your domain name).

THEN THE INTERNET EXPLODED..... AND LO THERE WAS A SHORTAGE OF NUMBERS......

Something like that anyway. Basically there came a time when because of the way numbers were allocated (numbers are allocated from a central repository, and big organisations got lots of numbers - called "Classes" like a "class A" or a "class C", but small organisations did not, they looked to be running out of numbers, because lots of small orgs wanted them and the big orgs were hogging all the numbers. So clever boffins, set up a system of VIRTUAL IP numbers, and it was called HTTP v1.1 and there was much rejoicing, and it was called Virtual Hosting.

And that meant that you could have a domain name even though you *don't* have your own IP number. And ISP's could host more people than they have IP numbers and that was all good, because then organisations began giving their classes back because they didn't need to hog them afterall.

WHY SHOULD YOU CARE WETHER YOU'RE VIRTUAL OR NOT?

There are still some things that you really need your own IP number for - I think that getting a Verisign certificate is one, and running a secure website is another.

If you have lots of visitors who have older browsers, or access the site through an older firewall then they may not ever see your website - they will see whatever the ISP has determined is the "default" webspace for that IP number. That's because some older browsers and firewalls don't run HTTP 1.1.

<disclaimer> I used to work for an ISP, so I think thats how it works, but of course it could be totally wrong, or your ISP may mean something different by virtual hosting, but thats what I think it means here.</disclaimer>


Thanks so much for your excellent explanation! I feel smarter already. :-)

As a follow-up clarification: Does that mean that multiple virtual domain names can resolve to the *same* IP address? (I'm drawing the map in my brain, and I'm trying to imagine the relationship between virtual domain names and IP addresses.)

Thanks again for sharing your wealth of knowledge on this!


Yep that's exactly what it means. Which is why if you're running a browser that's old, or an old firewall (or stupid firewall :-) then "results may vary".

<snip>

> Thanks again for sharing your wealth of knowledge on
> this!

Sometimes knowing this stuff is *really* useful - like if you have a virtual host, and someone says they don't see your page, but they see someone else's, but not *everyone* has that effect, then chances are their firewall is the problem (if they have a modern browser).

If you get lots of them then it would be worth asking your ISP for your own IP number.