Well, in truth there's a whole lot more that's dependent on how your LAN is set up....
IP addresses fall into one of two categories: dynamic and fixed. A fixed address always has the same address, and a dynamic one checks in with a special server whenever it needs one. Typically, that means when you turn it on.
That server, better known as a DHCP server, keeps track of the addresses and makes sure that no address is duplicated.
In my network, printers and servers have fixed IP addresses while computers have dynamic ones.
If your computer fails to get an address back from the DHCP server, it will take a default address of 169.254.something or other. If you see that, you're not getting a connection back from the DHCP server. I check the address by going to a command prompt and typing "ipconfig".
In my home network, my Linksys gateway/router serves as the DHCP server. If it's misbehaving, rebooting it can sometimes clean things up nicely.
So....
In your environment, if you've got a DHCP server already, you don't want to muck with that. You want to fix the problem with the DHCP server, and rebooting it is the best first step. Resetting it is a second step, but before doing that, you should make sure you know what settings were on there. It can be hard to recreate it from scratch...
Soooo..... again... what's your overall environment look like?
*edit* and after taking a look, your Devolo critter is just an ethernet card. It's not a self-contained DHCP server or anything like that, so the advice above about trying to string wire to your router/gateway makes sense. The problem appears to be either there or in your connection to there. Do other machines work in the network? Can you maintain the router (or modem, or whatever)? Are you suffering from geek overload yet?
[ 04-06-2007, 10:32 PM: Message edited by: Bungleau ]