Dns

I want to host more than one site on my computer with a single outside IP address. Multi .com's to single IP...can any one help?

running IIS, default web goes to main site, I need to add other .com registrations to seperate Webs or Virtual Webs on the same server.

Yes this is possible, once they are added into DNS this is an IIS issue. You need to configure host header info from your IIS Snap-in, there you can add different .com's for differnt site's or virutal servers.
I suggest you ask the folks in the IIS forum if you need help for the host-header config.

Cheers

This leads me to realise that DNS, other than easy-to-remember names, allows multiple websites to one IP.

Not that we can't do that without IP, just that the URL wouldn't be nice

DNS orchestrates it. But it is really the HTTP protocol that makes it possible to host more than 1 site on a single IP.

snippet of browser HTTP request:

GET /path/to/url/page.html HTTP/1.1
Host: www.domain.com
...

The webserver can choose where to look for the content based on the HOST. The browser sticks whatever server domain you placed in the address bar for the HOST. But really, anything at all can be used as the HOST. Many automated hacking scripts use "www" as the HOST. I have a virtual host in my apache to redirect all hack requests to a script which sends a messenger service notifcation to the requesting machine warning them of a possible virus.

LOL.

How is that done?

Well the old version of my virtual hosts look like this:

http://serialcoders.sytes.net/linked/vhosts.txt

And my script looks like this:

http://serialcoders.sytes.net/linked/exploit.txt

Nice =D

Unfortunately, I don't have access to my httpd.conf

How can they exploit your server anyway?

Well, if you're using IIS webserver then there is a huge risk that IIS won't properly handle a URL request. Most commonly, a hacker or hacking script may send a specially formatted URL to trick the server into executing a program outside of the site root directory (like the DOS command shell 8-0). By looking at my script you can see many of those requests as logged by my webserver. I use apache, so I'm immune to the all-so-common IIS exploits.

I host my site on my own computer which is why I have access to doing this fun stuff. :-) Oh, and once somebody actually emailed me asking what was up with my automated message. ;-)

Ok thanks a bunch =D