Imac to d-link

My apple imac g5 will no longer connect to my d-link 624 router. When I go to system preferences, network the first page the little light is yellow and the message says “Airport is connected to the network default. Airport has a self assigned IP address and may not be able to connect to the internet.” Default is the clever name of my wireless network. Pressing configure gives the following information:

Configure iPv4 using DHCP.
IP address: 169.254.196.94
Subnet mask: 255.255.0.0
Router:

Yes, for router it says nothing. I don’t recall if it used to have anything there or not.

Anyone know what is going on?