"Yannick Duch�ne (Hibou57)" <yannick_duchene@yahoo.fr> wrote in message 
news:op.wfvw0nytule2fv@douda-yannick...
...
>Web addresses have a domain name and a TLD, like in adalog.fr. The server 
>is reached via DNS request returning the IP addresse for the domain. Web 
>addresses may also have subdomains. An example could be archive.adaic.com. 
>"archive", is a subdomain of adaic.com. To reach the subdomain, you have 
>to contact the server at the IP address associated to the domain 
>adaic.com. That means archive.adaic.com has the same IP address as 
>adaic.com. The same goes for any other subdomain like news.mysite.net, 
>forum.mysite.net, wiki.mysite.net and so on, all reached via mysite.net's 
>IP.

Way off topic, but this description is quite wrong. "archive.adaic.com" runs 
on my web server, "adaic.com" runs on AdaCore's web server, and I'm pretty 
sure that AdaCore hasn't taken over my Internet and its IPs!

In fact, the subdomains are included in the DNS just like the domains, and 
can be found (directly) to have any IPs that you might desire. Indeed, 
subdomains are commonly used to direct mail to a different server than web 
traffic, as just one of many possible uses.

Your point was mainly about virtual hosting, which wasn't affected by this. 
(But my web server just does a direct string compare against a list of web 
sites, after the URL is normalized; no fancy pattern matching is used, it 
would be too expensive.)

                                                     Randy.