http://masterc.no-ip.org/tutorials/DHCP.html
I'll explain the pictures to you...
The first one you should look at is:
standard.png
This is the first screen. It's a fresh install, and although it's 9.0 the rules haven't changed much, everything should still apply.
The second one:
Software2.png
This is showing you where to go to in the Mandrake Control Center (which is the eighth icon over on the taskbar in my screenshot)
Click the connection icon and...
Network1.png
Should appear. At this point choose the wizard button at the bottom, you should now see:
Network2.png
Click the Auto Detection square, and then next, now we see:
network3.png
Here you will click on ADSL connection, and then click next:
network4.png
Make sure you've got the "use bootp/dhcp" checked. This configures everything for you. Now click next:
network5.png
Do not enter anything for your hostname, just click next:
network6.png
You need a restart, this will let you get on the internet without restarting the entire computer and just the network:
network7.png
Click finish of course
network8.png
The blackbox should actually contain a real IP, and have DHCP where mine shows lan. The important part is "connected" should be what you have showing.
And then in the white box below that, your IP address should again be a real IP (mine is fake) and your Protocol should say "dynamic" or "DHCP"
Ultimately, it should say "up".
If all this is working, click apply, and then OK.
Open up a browser and see if it works, if not, post back.
Cool