Why won't yahoo.com display as my homepage?

How does a homepage display by default when wirelessly connecting to a network.?

• i went to a internet cafe today and took my laptop. i scanned for wireless connections and spoted the cafes wifi connection witout a lock next to it so i clicked it and connected. the second i opened up internet explorer i saw a homepage which asked me to enter a login and password. what im wondering is how did they do this? if i had a wifi connection at home how can i set this up for myself to display a default homepage for all to see. i think this is better than setting up WEP since wep can be bruth forced within minutes.

• Answer:

  They are using re-direction. Basically they have a little server that gives you one IP address when you first browse that is 'in the open' and only lets you see that page. Once you have logged in you get a second IP address and usually a more secure connection. WEP is better than nothing. most access points allow MAC filtering (nothing to do with Apple - honest!). Every network device has a unique MAC address (typically on a label on the rear / bottom of the device. This combined with WEP is fairly good security as someone wanting to hack into your network has to work a lot harder.