I installed MacOsX 10.4.7 Jas on my Intel centrino duo laptop. All works fine, but i can't connect it to the internet.
(i have both ipw3945 wireless card and ethernet card)

Ifconfig results: lo0....
gif0
stf0
fw0...

If i try ifconfig en0 up, it shows me this massage: ifconfig: interface en0 does not exist.
If i go to SystemPreferences-->Network, the ethernt built-in is "obscured" (i can't click it) and there is only the "Firewire built-in".
When i go to System Profiler-->Network-->Positions it display me this:
automatic
active: yes
services:
ethernet built-in:
type: ethernet
name BSD: en0
IPv4
method: DHCP
What can i do???

I'm having a similar issue (very odd). If anyone has any advice, it would be much appreciated.

It knows you have an ethernet card but doesn't have the drivers

Look through http://forum.insanelymac.com/index.php?showtopic=34074

I have a Realtek 8110 and needed the driver package before it would show up in ifconfig or sys prefs

Bertie

I'm not sure if that's the case in my situation, because before I got the wireless working, the NIC was working fine. When I did the (well known) swap, changing en0 to en1, then the wireless worked but not the NIC anymore.