I was working on my MacBook Pro this morning and a few hours later I could not access the internet. I checked my network connections and I received an error saying "Airport does not have an IP address and cannot connest to the internet." I have no idea what could have caused this becuase I have not tampered with either the settings or the wireless router (which is a Linksys WRK54G). Any thoughts??
On a side note, I also went into the network settings to look at the TCP/IP tab since that what some people suggested and there is no IP address anywhere.
Cycle the power on the router; if that doesn't restore the IP address, then look at the settings within the router. Also, make sure that Airport is connecting to your router and not some other wireless network.