Sub Domain Names

[Dysan]

Hi, I'm intrigued to find out how the URL's on eBay work. The main domain name for eBay is: www.ebay.co.uk, but the signup page is www.signup.ebay.co.uk. How are the www.signup.ebay.co.uk (Sub domains) created?

[bpat1434]

Typically through your web hosts control panel. They point to a different document root folder.

Typically this is just an addition of a "VirtualHost" to the configuration file.

<VirtualHost *>
    ServerName sub.domain.tld
    ServerAlias www.sub.domain.tld
    DocumentRoot /path/to/httpd/docs
    ServerAdmin [e-mail]
</VirtualHost>

Please see VirtualHost in Apache's documentation. There are equivalent things for IIS and other servers.